Internal combustion engine and working cycle

ABSTRACT

The invention is concerned with a method of deriving mechanical work from a combustion gas in internal combustion engines and reciprocating internal combustion engines for carrying out the method. The invention includes methods and apparatuses for managing combustion charge densities, temperatures, pressures and turbulence in order to produce a true mastery within the power cylinder in order to increase fuel economy, power, and torque while minimizing polluting emissions. In its preferred embodiments, the method includes the steps of (i) producing an air charge, (ii) controlling the temperature, density and pressure of the air charge, (iii) transferring the air charge to a power cylinder of the engine such that an air charge having a weight and density selected from a range of weight and density levels ranging from below atmospheric weight and density to heavier-than-atmospheric weight and density is introduced into the power cylinder, and (iv) then compressing the air charge at a lower-than-normal compression ratio (v) causing a pre-determined quantity of charge-air and fuel to produce a combustible mixture, (vi) causing the mixture to be ignited within the power cylinder, and (vii) allowing the combustion gas to expand against a piston operable in the power cylinders with the expansion ratio of the power cylinders being substantially greater than the compression ratio of the power cylinders of the engine. In addition to other advantages, the invented method is capable of producing mean effective cylinder pressures ranging from lower-than-normal to higher-than-normal. In the preferred embodiments, the mean effective cylinder pressure is selectively variable (and selectively varied) throughout the mentioned range during the operation of the engine. In an alternate embodiment related to constant speed-constant load operation, the mean effective cylinder pressure is selected from the range and the engine is configured, in accordance with the present invention, such that the mean effective cylinder pressure range is limited, being varied only in the amount required for producing the power, torque and speed of the duty cycle for which the engine is designed.

[0001] This invention relates to a method of deriving mechanical workfrom combusting gas in an internal combustion engine by means of a newthermodynamic working cycle and to reciprocating, internal combustionengines for carrying out the method.

BACKGROUND OF INVENTION

[0002] It is well known that as the expansion ratio of an internalcombustion engine is increased, more energy is extracted from thecombustion gases and converted to kinetic energy and the thermodynamicefficiency of the engine increases. It is further understood thatincreasing air charge density increases both power and fuel economy dueto further thermodynamic improvements. The objectives for an efficientengine are to provide a high-density charge, begin combustion at maximumdensity and then expand the gases as far as possible against a piston.

[0003] Conventional engines have the same compression and expansionratios, the former being limited in spark-ignited engines by the octanerating of the fuel used. Furthermore, since in these engines theexploded gases can be expanded only to the extent of the compressionratio of the engine, there is generally substantial heat and pressure inthe exploding cylinder which is dumped into the atmosphere at the timethe exhaust valve opens resulting in a waste of energy and producingunnecessarily high polluting emissions.

[0004] Many attempts have been made to reduce the compression ratio andto extend the expansion process in internal combustion engines toincrease their thermodynamic efficiency, the most notable one being the“Miller” Cycle engine, developed in 1947.

[0005] Unlike a conventional 4-stroke cycle engine, where thecompression ratio equals the expansion ratio in an given combustioncycle, the Miller Cycle engine is a variant, in that the parity isaltered intentionally. The Miller Cycle uses an ancillary compressor tosupply an air charge, introducing the charge on the intake stroke of thepiston and then closing the intake valve before the piston reaches theend of the inlet stroke. From this point the gases in the cylinder areexpanded to the maximum cylinder volume and then compressed from thatpoint as in the normal cycle. The compression ratio is then establishedby the volume of the cylinder at the point that the inlet valve closed,being divided by the volume of the combustion chamber. On thecompression stroke, no actual compression starts until the pistonreaches the point the intake valve closed during the intake stroke, thusproducing a lower-than-normal compression ratio. The expansion ratio iscalculated by dividing the swept volume of the cylinder by the volume ofthe combustion chamber, resulting in a more-complete-expansion, sincethe expansion ratio is greater than the compression ratio of the engine.

[0006] In the 2-stroke engine the Miller Cycle holds the exhaust valveopen through the first 20% or so of the compression stroke in order toreduce the compression ratio of the engine. In this case the expansionratio is probably still lower than the compression ratio since theexpansion ratio is never as large as the compression ratio inconventional 2-stroke engines.

[0007] The advantage of this cycle is the possibility of obtaining anefficiency higher than could be obtained with an expansion ratio equalto the compression ratio. The disadvantage is that the Miller Cycle hasa mean effective pressure lower than the conventional arrangement withthe same maximum pressure, but with no appreciable improvements inemissions characteristics.

[0008] The Miller Cycle is practical for engines that are not frequentlyoperated at light-loads, because at light-load operation the meancylinder pressure during the expansion stroke tends to be near to, oreven lower than, the friction mean pressure. Under such circumstancesthe more-complete-expansion portion of the cycle may involve a net lossrather than a gain in efficiency.

[0009] This type of engine may be used to advantage where maximumcylinder pressure is limited by detonation or stress considerations andwhere a sacrifice of specific output is permissible in order to achievethe best possible fuel economy. The cycle is suitable only for enginesthat operate most of the time under conditions of high mechanicalefficiency, that is, at relatively low piston speeds and near full load.

SUMMARY OF THE INVENTION

[0010] Briefly described, the present invention comprises an internalcombustion engine system (including methods and apparatuses) formanaging combustion charge densities, temperatures, pressures andturbulence in order to produce a true mastery within the power cylinderin order to increase fuel economy, power, and torque while minimizingpolluting emissions. In its preferred embodiments, the method includesthe steps of (i) producing an air charge, (ii) controlling thetemperature, density and pressure of the air charge, (iii) transferringthe air charge to a power cylinder of the engine such that an air chargehaving a weight and density selected from a range of weight and densitylevels ranging from atmospheric weight and density to aheavier-than-atmospheric weight and density is introduced into the powercylinder, and (iv) then compressing the air charge at alower-than-normal compression ratio, (v) causing a pre-determinedquantity of charge-air and fuel to produce a combustible mixture, (vi)causing the mixture to be ignited within the power cylinder, and (vii)allowing the combustion gas to expand against a piston operable in thepower cylinder with the expansion ratio of the power cylinder beingsubstantially greater than the compression ratio of the power cylindersof the engine. In addition to other advantages, the invented method iscapable of producing mean effective [cylinder] pressures (“mep”) in arange ranging from lower-than-normal to higher-than-normal. In thepreferred embodiments, the mean effective cylinder pressure isselectively variable (and selectively varied) throughout the mentionedrange during the operation of the engine. In an alternate embodimentrelated to constant speed-constant load operation, the mean effectivecylinder pressure is selected from the range and the engine isconfigured, in accordance with the present invention, such that the meaneffective cylinder pressure range is limited, being varied only in theamount required for producing the power, torque and speed of the dutycycle for which the engine is designed.

[0011] In its preferred embodiments, the apparatus of the presentinvention provides a reciprocating internal combustion engine with atleast one ancillary compressor for compressing an air charge, anintercooler through which the compressed air can be directed forcooling, power cylinders in which the combustion gas is ignited andexpanded, a piston operable in each power cylinder and connected to acrankshaft by a connecting link for rotating the crankshaft in responseto reciprocation of each piston, a transfer conduit communicating thecompressor outlet to a control valve and to the intercooler, a transfermanifold communicating the intercooler with the power cylinders throughwhich manifold the compressed charge is transferred to enter the powercylinders, an intake valve controlling admission of the compressedcharge from the transfer manifold to said power cylinders, and anexhaust valve controlling discharge of the exhaust gases from said powercylinders. For the 4-stroke engine of this invention, the intake valvesof the power cylinders are timed to operate such that charge air whichis equal to or heavier than normal can be maintained within the transfermanifold when required and introduced into the power cylinder during theintake stroke with the intake valve closing at a point substantiallybefore piston bottom dead center position or, alternatively, with theintake valve closing at some point during the compression stroke, toprovide a low compression ratio. In some designs another intake valvecan open and close quickly after the piston has reached the point thefirst intake valve closed in order to inject a temperature adjusted highpressure secondary air charge still at such a time that the compressionratio of the engine will be less than the expansion ratio, and so thatignition can commence at substantially maximum charge density. The2-stroke engine of this invention differs in that the intake valves ofthe power cylinders are timed to operate such that an air charge ismaintained within the transfer manifold and introduced into the powercylinder during the scavenging-compression (the 2nd) stroke at such atime that the power cylinder has been scavenged by low pressure air andthe exhaust valve has closed, establishing that the compression ratio ofthe engine will be less than the expansion ratio of the power cylinders.Means are provided for causing fuel to be mixed with the air charge toproduce a combustible gas, the combustion chambers of the powercylinders are sized with respect to the displaced volume of the powercylinder such that the exploded combustion gas can be expanded to avolume substantially greater than the compression ratio of the powercylinder of the engine.

[0012] The chief advantages of the present invention over existinginternal combustion engines are that it provides a compression ratiolower than the expansion ratio of the engine, and provides, selectively,a mean effective cylinder pressure higher than the conventional enginearrangement with the same or lower maximum cylinder pressure than thatof prior art engines.

[0013] This allows greater fuel economy, and production of greater powerand torque at all RPM, with low polluting emissions. Because chargedensities, temperatures and pressures are managed, light-load operationis practical even for extended periods, with no sacrifice of fueleconomy. The new working cycle is applicable to 2-stroke or 4-strokeengines, both spark-ignited and compression-ignited. For spark-ignitedengines the weight of the charge can be greatly increased without theusual problems of high peak temperatures and pressures with the usualattendant problem of combustion detonation and pre-ignition. Forcompression-ignited engines the heavier, cooler, more turbulent chargeprovides low peak cylinder pressure for a given expansion ratio andallows richer, smoke-limited air-fuel ratio giving increased power withlower particulate and NO_(x) emissions. Compression work is reduced dueto reduced heat transfer during the compression process. Enginedurability is improved because of an overall cooler working cycle and acooler than normal exhaust. It also provides a means of regenerativebraking for storing energy for subsequent positive power cycles withoutcompression work and for transient or “burst” power which furtherincreases the overall efficiency of the engine.

[0014] All of the objects, features and advantages of the presentinvention cannot be briefly stated in this summary, but will beunderstood by reference to the following specifications and theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Embodiments of internal combustion engines according to theinvention will now be described, by way of example, with reference tothe accompanying drawings, in which:

[0016]FIG. 1 is a perspective view (with portions in cross-section) ofthe cylinder block and head of a six cylinder internal combustion engineoperating in a 4-stroke cycle, and representing a first embodiment ofthe apparatus of the present invention from which a first method ofoperation can be performed and will be described. Among its othercomponents, this embodiment is seen as having one ancillary compressor,a cooling system and valves to control charge pressures, density andtemperature.

[0017]FIG. 2 is a schematic drawing of a six cylinder internalcombustion engine similar to the engine of FIG. 1. operating in a4-stroke cycle, and representing a second embodiment of the apparatus ofthe present invention from which a second method of operation can beperformed and will be described. Among its other components, thisembodiment is seen as having two compressors, three intercoolers, fourcontrol valves, dual air paths for both the primary and the ancillarycompressors, dual manifolds and showing a means of controllingcharge-air pressures, density and temperatures.

[0018]FIG. 3 is a perspective view (with portions in cross-section) ofthe cylinder block and head of a six cylinder internal combustion engineoperating in a 4-stroke cycle, and representing a third embodiment ofthe apparatus of the present invention from which a third method ofoperation can be performed and will be described.

[0019]FIG. 4 is a perspective view (with portions in cross-section) ofthe cylinder block and head of a six cylinder internal combustion engineoperating in a 4-stroke cycle, and representing a fourth embodiment ofthe apparatus of the present invention from which a fourth method ofoperation can be performed and will be described. Among its othercomponents, this embodiment is seen as having an ancillary compressor,with two charge-air intake ducts and dual intake air routes, one ofwhich is low pressure and one which is high pressure, and both leadingto the same power cylinder, a cooling system and valves for controllingcharge-air pressures, density and temperature and an ancillaryatmospheric air intake system.

[0020]FIG. 4-B is a perspective view (with portions in cross-section) ofan engine similar to the engine of FIG. 4 with the exception that thereis only one atmospheric air intake which supplies charge-air to thepower cylinders at two different pressure levels.

[0021]FIG. 4-C is a schematic view of an exhaust and an air intakesystem of an engine showing a means of re-burning exhaust gases in orderto reduce polluting emissions.

[0022]FIG. 5 is a perspective view (with portions in cross-section) ofthe cylinder block and head of a six cylinder internal combustion engineoperating in a 4-stroke cycle, and representing a fifth embodiment ofthe apparatus of the present invention from which a fifth method ofoperation can be performed and will be described. Among its othercomponents, this embodiment is seen as having one atmospheric airintake, an ancillary compressor with two charge-air routes, one of whichis low pressure and which has two optional routes, and one which is highpressure, both leading to the same power cylinder, and control valvingmeans and air coolers for varying charge densities, pressures andtemperatures in the combustion chamber of the engine.

[0023]FIG. 6 is a part sectional view through one power cylinder of the4-stroke engine of FIG. 4, FIG. 4-B, FIG. 5, FIG. 7 or FIG. 33 at theintake valves showing an alternative method (adaptable to otherembodiments of the present invention) of preventing charge-air back flowand of automatically adjusting the charge pressure-ratio of the cylinderduring the air charging process.

[0024]FIG. 7 is a schematic drawing of a six cylinder, 4-stroke enginerepresenting yet another embodiment of the apparatus of the presentinvention, from which yet another method of operation can be performedand will be described, and depicting three alternative systems (two inphantom lines) of inducting a low pressure primary air charge. Among itsother components, this embodiment is seen as having three air coolersand dual manifolds and the means of controlling the temperature, densityand pressure of the charge by an engine control module and by valvingvariations.

[0025]FIG. 8 is a perspective view (with portions in cross-section) ofthe cylinder block and head of a six cylinder internal combustionengine, operating in a 2-stroke cycle, and representing a first 2-strokeembodiment of the apparatus of the present invention from which stillanother method of operation can be performed and will be described.Among its other components, this embodiment is seen as having a primaryand an ancillary compressor, a cooling system and conduits and valves toadjust charge density, temperature and pressure according to theinvention.

[0026]FIG. 9 is a perspective view (with portions in cross-section) ofthe cylinder block and head of a six cylinder internal combustion engineoperating in a 2-stroke cycle, and representing a second 2-strokeembodiment of the apparatus of the present invention from which stillanother method of operation of can be performed and will be described.Among its other components, this embodiment is seen as having oneatmospheric air intake, a primary and an ancillary compressor, with twocharge-air routes, one of which is low pressure which has alternateroutes, and one of which is high pressure, and both leading to the samepower cylinder, and control valving means and air coolers for varyingcharge densities, pressures and temperatures in the combustionchamber-of the engine.

[0027]FIG. 9-B is a schematic drawing of a six cylinder, 2-stroke enginerepresenting yet another embodiment of the apparatus of the presentinvention, from which yet another method of operation can be performedand will be described, and depicting two alternative systems (one inphantom lines) of inducting a low pressure primary air charge. Among itsother components, this embodiment is seen as having three air coolersand dual manifolds and the means of controlling the temperature, densityand pressure of the charge by an engine control module and by valvingvariations.

[0028]FIG. 10 is a part sectional view through one power cylinder of the2-stroke engine of FIG. 9. at the intake valves, showing an alternativemethod (adaptable to other embodiments of the present invention) ofpreventing charge-air back flow during high pressure air charging andshowing a pressure balanced valve having a pumped oil/air coolingsystem.

[0029]FIG. 11 is a perspective view (with portions in cross-section) ofthe cylinder block and head of a six cylinder internal combustion engineoperating in a 2-stroke cycle, and representing a third 2-strokeembodiment of the apparatus of the present invention from which stillanother method of operation of can be performed and will be described.Among its other components, this embodiment is seen as having a primaryand an ancillary compressor, a cooling system and conduits and valves toadjust charge density, temperature and pressure and having a single airintake runner for each power cylinder with at least two intake valvesarranged in such a manner that one intake valve can operate with timingindependent of the other intake valve.

[0030]FIG. 12 is a pressure-volume diagram comparing the cycle of theengine of this invention with that of a high-speed diesel engine.

[0031]FIG. 13 is a chart showing improvements possible in the engine ofthis invention in effective compression ratios, peak temperatures andpressures, charge densities and expansion ratios, in comparison with apopular heavy-duty 2-stroke diesel engine.

[0032]FIG. 14 is a chart showing improvements possible in the engine ofthis invention in effective compression ratios, peak temperatures andpressures, charge densities and expansion ratios, in comparison with apopular heavy-duty, 4-stroke diesel engine.

[0033]FIG. 15 is a schematic drawing of suggested operating parametersfor operation of the engines, both 2-stroke and 4-stroke, of FIGS. 5-7and FIGS. 9-10 showing dual intercoolers for the main compressor, asingle intercooler for a secondary compressor and a control system andvalves for selecting different charge-air paths for light-loadoperations, and depicting (one in phantom lines) two alternative systemsof inducting a low pressure primary air charge.

[0034]FIG. 16 shows suggested valve positions for supplying manifolds 13and 14 with an air charge optimum for medium-load operation for theengines of FIGS. 5-7 and FIGS. 9-10. For medium-load operation theshutter valve 5 of compressor 2 would be closed and the air bypass valve6 would be open to pass the air charge uncooled without compression tothe intake of compressor 1 where closed shutter valve 3 and closed airbypass valve 4 directs the air charge now compressed by compressor 1past the intercoolers to manifolds 13 and 14 with the air compressed andheated by compressor 1, for medium-load operation.

[0035]FIG. 17 shows a suggested scenario for providing the engines ofFIGS. 5-7 and FIGS. 9-10 with a high density air charge for heavy duty,high power output operation. FIG. 17 shows all shutter valves 5 and 3and all air bypass valves 6 and 4 closed completely so that the primarystage of compression is operative and a second stage of compression isoperative and the entire air charge, with the exception of any goingthrough conduit 32 to intake valve 16-B. is being passed through theintercoolers 10, 11 and 12 to produce a very high density air charge tomanifolds 13 and 14 and to the engines power cylinders for heavy-loadoperation.

[0036]FIG. 18 shows a schematic drawing representing any of the enginesof FIG. 3-FIG. 11, depicting an alternative type of auxiliary compressor2′ and a system of providing a means for disabling or cutting out theauxiliary compressor when high charge pressure and density is notneeded. For relieving compressor 2′ of work, shutter valve 5 is closedand air bypass valve is opened so that air pumped through compressor 2′can re-circulate through compressor 2′ without requiring compressionwork.

[0037]FIG. 19 is a schematic drawing representing the engines shown inFIGS. 5-7 and FIGS. 9-10 and having two compressors, and one intercoolerfor one stage of compression, dual intercoolers for a second stage ofcompression, dual manifolds, four valves and an engine control module(ECM) and illustrating means of controlling charge-air density, pressureand temperature by varying directions and amounts of air flow throughthe various electronic or vacuum operated valves and their conduits.

[0038]FIG. 20 is a schematic drawing showing optional electric motordrive of the air compressors of the engines of FIG. 1 through FIG. 11.

[0039]FIG. 21 is a schematic transverse sectional view of apre-combustion chamber, a combustion chamber and associated fuel inletducts and valving suggested for gaseous or liquid fuel operation for theengines of this invention or for any other internal combustion engine.

[0040]FIG. 22 is a part sectional view through one cylinder of an engineshowing an alternate construction whereby there is supplied two firingstrokes each revolution of the shaft for a 2-stroke engine and onefiring stroke each revolution of the shaft for a 4-stroke engine, havinga beam which pivots on its lower extremity, a connecting rod which isjoined mid-point of the beam and is fitted to the crankshaft of theengine, and whereby a means is provided for varying the compressionratio of the engine at will.

[0041]FIG. 23 is a part sectional view through one cylinder of an engineshowing an alternate construction whereby there is supplied two firingstrokes each crankshaft revolution for a 2-stroke engine and one firingstroke each revolution of the shaft for a 4-stroke engine, and wherebythe beam connecting the connecting rod and the piston pivots at a pointbetween the piston and the piston connecting rod, which connecting rodis attached to the crankshaft of the engine, and an alternate preferredmeans of power take-off from the piston by a conventional piston rod,cross-head and connecting rod arrangement.

[0042]FIG. 24 is a part sectional view through one cylinder of an engineshowing a means of providing extra burn-time each firing stroke in a2-stroke or 4-stroke engine.

[0043]FIG. 25 is a perspective view of the cylinder block and head of asix cylinder internal combustion engine operating in a 2-stroke cycleand representing a yet another embodiment of the apparatus of thepresent invention from which still another method of operation of can beperformed and will be described. Among its other components, thisembodiment is seen as having scavenging ports in the bottom of thepiston sleeves and having a primary and an ancillary compressor, acooling system, valves and conduits to control the pressure, density andtemperature of the charge-air, and valves and conduits to supplyscavenging air to the cylinders.

[0044]FIG. 26 is a schematic drawing of an engine similar to the engineof FIG. 25 showing one intercooler for one optional stage ofcompression, dual intercoolers for a primary compression stage andshowing a control system (including engine control module (ECM) andvalving) for controlling charge-air density, weight, temperature andpressure by controlling directions and amounts of air flow through thevarious valves, conduits and an optional throttle valve, and showing twooptional routes for supplying scavenging air to the scavenging ports inthe bottom of the cylinders, and alternative routes for the exhaustedgases to exit the engine.

[0045]FIG. 27 through FIG. 30 are schematic drawings of the engine ofFIG. 25 and FIG. 26 showing four alternate methods suggested forefficient scavenging of the engines. FIG 27 and FIG. 28 also show aschematic drawing for an engine control module (ECM) and valving tocontrol charge-air and scavenging air at a pressure, density andtemperature deemed appropriate for each.

[0046]FIG. 31 is a schematic drawing showing suggested optional electricmotor drive for the engine s air compressors.

[0047]FIG. 32 is a schematic drawing of the 2-stroke engine of FIG. 25and FIG. 26, having only one compressor for supplying both charge-airand scavenging air, and showing a control system and means ofcontrolling charge and scavenging air at a pressure, density andtemperature deemed appropriate for each, and showing means of channelingthe air through different paths for the same purpose;

[0048]FIG. 33 is a schematic transverse sectional view through a sixcylinder engine having two compressor cylinders, four power cylinders,one supercharger, five regulatory valves, and showing an engine controlmodule (ECM) for controlling charge temperatures, density and weight,and adopted for storage of compressed air compressed by regenerativebraking, or for storage of bleed-air produced in some industrialprocesses, in any of the engines of this invention.

[0049]FIG. 34 is a schematic drawing representing any of the engines ofthe present invention and showing an alternate embodiment which includesa separate, electric-powered air compressor and, alternatively, anentrance conduit leading from a supply of waste or “bleed” compressedair for supplying charge-air to the engine (or to a plurality ofengines), whereby the need for engine-powered compressors is eliminated.

[0050]FIG. 35 is a schematic drawing representing any of the engines ofthe present invention depicted in an alternate embodiment which isconfigured to operate as a constant load and constant speed engine. Thisconstant load and constant speed engine embodiment of the presentinvention is shown as including both a primary and an ancillarycompressor with optional intercoolers for providing two stages ofpre-compressed charge-air, either optionally intercooled oradiabatically compressed.

[0051]FIG. 36 is a schematic drawing representing any of the engines ofthe present invention, and depicting a constant load and constant speedengine in accordance with an alternate embodiment of the presentinvention in which there is provided a single compressor with optionalintercoolers for providing a single stage of pre-compressed charge-air,either optionally intercooled or adiabatically compressed.

DETAILED DESCRIPTION OF THE DRAWINGS

[0052] With reference now in greater detail to the drawings, a pluralityof alternate, preferred embodiments of the apparatus of the ImprovedInternal Combustion Engine 100 of the present invention are depicted.Like components will be represented by like numerals throughout theseveral views; and, in some but not all circumstances, as the writermight deem necessary (due to the large number of embodiments), similarbut alternate components will be represented by superscripted numerals(e.g., 100 ¹). When there are a plurality of similar components, theplurality is often times referenced herein (e.g., six cylinders 7 a-7f), even though fewer than all components are visible in the drawing.Also, components which are common among multiple cylinders are sometimeswritten with reference solely to the common numeral, for ease ofdrafting—e.g. piston 22 a-22 f=>piston 22. In an effort to facilitatethe understanding of the plurality of embodiments, (but not to limit thedisclosure) some, but not all, sections of this Derailed Description aresub-titled to reference the system or sub-system detailed in the subjectsection.

[0053] The invented system of the present invention is, perhaps, bestpresented by reference to the method(s) of managing combustion chargedensities, temperatures, pressures and turbulence; and the followingdescription attempts to describe the preferred methods of the presentinvention by association with and in conjunction with apparatusesconfigured for and operated in accordance with the alternate, preferredmethods.

[0054] Some, but not necessarily all, of the system components that arecommon to two or more of the herein depicted embodiments include acrankshaft 20, to which are mounted connecting rods 19 a-19 f, to eachof which is mounted a piston 22 a-22 f; each piston traveling within apower cylinder 7 a-7 f; air being introduced into the cylinders throughinlet ports controlled by intake valves 16, and air being exhausted fromthe cylinders through exhaust ports controlled by exhaust valves 17. Theinteraction, modification and operation of these and such othercomponents as are deemed necessary to an understanding of the variousembodiments of the present invention are expressed below.

The Engine 100 ¹ of FIG. 1

[0055] Referring now to FIG. 1, there is shown a six cylinderreciprocating internal combustion engine 100 ¹ in which all of thecylinders 7 a-7 f(only one of which is shown in a sectional view) andassociated pistons 22 a-22 f operate in a 4-stroke cycle and all powercylinders are used for producing power to a common crankshaft 20 viaconnecting rods 19 a-19 f, respectively. An ancillary compressor 2(herein depicted as a Lysholm rotary compressor) selectably supplies airwhich has been compressed, or allows delivery of air therethrough atatmospheric pressure, to manifolds 13 and 1 and to cylinders 7 a-7 f,which cylinders operate in a 4-stroke cycle. Valves 3, 5 and 6 andintercoolers 10, 11 and 12 are used. in the preferred embodiments, tocontrol air charge density, weight, temperature and pressure. The intakevalves 16 a-16 f, 16 a′-16 f are timed to control the compression ratioof the engine 100 ¹. The combustion chambers are sized to establish theexpansion ratio of the engine.

[0056] The engines 100 ¹-100 ⁵, 100 ⁷ of FIG. 1, FIG. 2, FIG. 3, FIG. 4,FIG. 5, and FIG. 7, respectively, have camshafts 21 fitted with cams andare arranged to be driven at one-half the speed of the crankshaft inorder to supply one power stroke for every two revolutions of thecrankshaft, for each power piston. The rotary compressors 2 of FIG. 1,FIG. 2, FIG. 3, FIG. 4, FIG. 4-B, FIG. 5, FIG. 7 and FIG. 33 can bedriven by a ribbed V-belt and would have a step-up gear between the Vpulley and the compressor drive shaft, the rotary compressors could alsobe fitted with a variable-speed step-up gear as in some aircraftengines. The reciprocating compressor 1 of FIG. 3 is shown as havingdouble-acting cylinders linked to the crankshaft 20 by a connecting rod19 g; and the crankshaft 20 to which it is linked by connecting rod 19 gwould supply two working strokes for each revolution of the crankshaft20. In one alternate approach, the reciprocating compressor 1 is drivenby the connecting rod 19 g being connected to a short crankshaft abovethe main crankshaft 20 to which the ancillary crankshaft (not shown)would be geared by a step-up gear in order to provide more than twoworking strokes per revolution of the main crankshaft 20. Alternatively,the compressor system can have multiple stages of compression for eitherrotary or reciprocating compressors. Whereas, the ancillary compressor 1and second ancillary compressor 2 of the various embodiments aredepicted throughout as a reciprocating compressor or a rotarycompressor, it is noted that the invention is not limited by the type ofcompressor utilized for each; and the depicted compressors may beinterchanged, or may be the same, or may be other types of compressorsperforming the functions described herein.

[0057] The engine 100 ¹ shown in FIG. 1 is characterized by a moreextensive expansion process, a low compression ratio and the capabilityof producing a combustion charge varying in weight fromlighter-than-normal to heavier-than-normal, and capable of providing,selectively, a mean effective cylinder pressure higher than can theconventional arrangement of normal engines but capable of having a lowermaximum cylinder pressure in comparison to conventional engines. Anengine control module (ECM) (not shown in FIG. 1) and variable valves 3,5 and 6 on conduits, as shown, provide a system for controlling thecharge density, pressure, temperature, and the mean and peak pressurewithin the cylinder which allows greater fuel economy, production ofgreater torque and power at low RPM, with low polluting emissions forboth spark and compression-ignited engines. In alternate embodiments, avariable valve timing system can be used and, with a control system suchas an ECM, can control the time of opening and the time of closing ofthe intake valves 16 and 16′ to further provide an improved managementof conditions in the combustion chambers of cylinders 7 a-7 f of theengine 100 ¹ to allow for a flatter torque curve and higher power, whenneeded, and with low levels of both fuel consumption and pollutingemissions.

Brief Description of Operation of the engine 100 ¹ shown in FIG. 1

[0058] The engine 100 ¹ of this invention shown in FIG. 1 is a highefficiency engine that attains both high power and torque with low fuelconsumption and low polluting emissions. The new working cycle is anexternal compression type combustion cycle. In this cycle, part of theintake air (all of which is compressed in the power cylinders inconventional engines) is, selectively, compressed by at least oneancillary compressor 2. The temperature rise during compression can besuppressed by use of air coolers 10, 11, 12 which cool the intake air,and by a shorter compression stroke.

[0059] One suggested, preferred method of operation of the new-cycleengine 100 ¹ is thus:

[0060] 1. Depending upon the power requirements of the engine (e.g.,differing load requirements), either intake air at atmospheric pressureor intake air that has been compressed by at least one ancillarycompressor 2 and has had its temperature and pressure controlled bybypass systems and charge-air coolers, is drawn into the power cylinder7 by the intake stroke of piston 22.

[0061] 2. (a) After the intake stroke is complete, the intake valve 16(which can be single or multiple, 16, 16′) is left open for a period oftime after the piston 22 has passed bottom dead center, which pumps partof the fresh air charge back into the intake manifold 13, 14. The intakevalve 16, 16′ is then closed at a point which action seals the cylinder7, thus establishing the compression ratio of the engine.

[0062]  (b) Alternatively, the intake valve 16, 16′ is closed early,during the intake stroke, before the piston 22 has reached bottom deadcenter. The trapped air charge is then expanded to the full volume ofthe cylinder 7 and compression of the charge starts when the piston 22returns to the point in the compression stroke at which the intake valve16, 16′ closed.

[0063] 3. (a) During the compression stroke of piston 22, at the pointthe intake valve 16 closed, either in 2(a) or 2(b) operation,compression begins, producing a small compression ratio. This makes itpossible to restrain the temperature rise during the compression stroke.

[0064]  (b) During light-load operation, such as in vehicle cruising orlight-load power generation, the shutter valve 5 is closed and the airbypass valve (ABV) 6 on the compressor is, preferably opened so that theintake air is returned to the intake conduit 8 of the compressor 2without being compressed. Shutter valve 3 can then direct the air chargearound or through intercoolers 11 and 12. During this time, the enginepistons 22 a-22 f are drawing in naturally aspirated air through thecompressor 2. This reduces compressor drive work and improves fueleconomy.

[0065]  (c) When more power is required, the charge density and pressurecan be increased by closing air bypass valve (ABV) 6 causing compressor2 to raise the air pressure and, alternatively, this can be accomplishedby either cutting in a second stage of compression by compressor 1, asshown in FIG. 2, or by increasing the speed of compressor 2. At the sametime, control valves 5 and 3 preferably, direct some or all of the aircharge through one or more of intercoolers 10, 11, and 12 in order toincrease charge-air density.

[0066] 4. Compression continues, fuel is added, if not already present,the charge is ignited and combustion produces a large expansion of thegases against the piston 22 producing great energy in either mode 3(a),(b) or (c). This energy produces a high mean effective cylinder pressureand is converted into high torque and power, especially in mode (c).

Detailed Description of Operation of the Engine 100 ¹ of FIG. 1

[0067] During the intake (1st) stroke of the piston 22 air flows throughair conduits 15 from a manifold of air 13 or 14, which air (depending onpower requirements) is either at atmospheric pressure or has beencompressed to a higher pressure by compressor 2, through the intakevalve 16 into the cylinder 7. During the intake stroke of piston 22 theintake valve 16 closes early (at point x). From this point, the cylinder7 contents are expanded to the maximum volume of the cylinder. Then,during the compression (2nd) stroke, no compression takes place untilthe piston 22 has returned to the point x where the intake valve 16 wasclosed during the intake stroke. (At point x, the remaining displacedvolume of the cylinder is divided by the volume of the combustionchamber, to establish the compression ratio of the engine.)Alternatively, during the intake (1st) stroke of piston 22, the intakevalve 16 is held open through the intake stroke and past bottom deadcenter piston position, and through part of the compression (2nd) strokefor a significant distance, 10% or, to perhaps 50% or more of thecompression stroke, thus pumping some of the charge-air back into intakemanifold 13 or 14, and the intake valve 16 then closes to establish alow compression ratio in the cylinders of the engine. At the time ofclosure of intake valve 16, the density, temperature and pressure of thecylinder will be at approximate parity with the manifold 13 or 14contents.

[0068] During light-load operation, such as in vehicle cruising orlight-load power generation, the shutter valves 5 and 3 are closed andthe air bypass valve (ABV) 6 on the compressor is, preferably, opened sothat the intake air is returned to the intake conduit 8 of thecompressor 2 without being compressed. During this time the enginepistons 22 a-22 f are drawing in naturally aspirated air through thecompressor 2. This reduces compressor drive work and improves fueleconomy.

[0069] When medium torque and power is needed, such as highway drivingor medium electric power generation, preferably the shutter valve 5 tocompressor 2 is closed and the air bypass valve (ABV) 6 is closed also.This causes the atmospheric pressure intake air to cease re-circulatingthrough the compressor 2 and the compressor 2 begins to compress thecharge-air to a higher-than-atmospheric pressure, while the closedshutter valves 5 and 3 direct the charge-air through conduits 104, 110,111, and 121/122 bypassing the air coolers 10, 11 and 12, with thecharge-air going directly to the manifolds 13 and 14 to power cylinders7 a-7 f where the denser, but hot, charge increases the mean effectivecylinder pressure of the engine to create greater torque.

[0070] When more power is needed, such as when rapid acceleration isneeded or for heavy-load electric power generation, preferably the airbypass valve (ABV) 6 is closed and the shutter valves 3 or 5 or both areopened. This causes the compressor 2 to compress all of the air charge.Shutter valves 3 or 5 or both then supply (depending on the respectiveopened/closed conditions of valves 3 and 5), the conditioned air chargethrough conduits 105 or 104, to conduit 110, and then through conduits111 or 112 to the manifolds, 13, 14 and to the cylinders 7 a-7 f viaone, two, or all three of the charge coolers 10, 11 and 12. The verydense cooled air charge when mixed with fuel and ignited and expandedbeyond the compression ratio of the engine produces great torque andpower.

[0071] When greater power is needed the charge-air density and weightcan be increased by increasing the speed of the compressor 2 or bycutting in a second compressor as in FIG. 2, for a second stage ofpre-compression. The latter can be done by the engine control module 27signaling air bypass valve (ABV) 6, FIG. 2. to close to-preventre-circulation of part of the intake air into conduit 103 which negates,selectively, any second compression stage during light-load operation.At the time air density and pressure is increased, shutter valves 3 and5 can direct part of all of the air charge through intercoolers 10, 11and 12 in order to condense the charge and lessen the increase in thecharge temperature and pressure, both accomplished by the cooling of thecharge. This increases the mean effective cylinder pressure duringcombustion for high torque and power.

[0072] The heavier the weight of the air charge and the denser thecharge, the earlier in the intake stroke (or the later in thecompression stroke) the intake valve can be closed to establish a lowcompression ratio and retain power, and the less heat and pressure isdeveloped during compression in the cylinder. In this 4-stroke enginethe intake charge can be boosted in pressure by as much as 4-5atmospheres and if the compression ratio is low enough, say 4:1 to 8:1(higher for diesel fuel), even spark-ignited there would be no problemwith detoniation. The expansion ratio should still be large, 14:1 wouldbe a preferred expansion ratio for spark ignition, perhaps 19:1 fordiesel operation.

[0073] The compression ratio is established by the displaced volume ofthe cylinder 7 remaining after point x has been reached in thecompression stroke (and intake valve 16 is closed) being divided by thevolume of the combustion chamber. The expansion ratio in all cases isgreater than the compression ratio. The expansion ratio is establishedby dividing the total displaced volume of the cylinder by the volume ofthe combustion chamber.

[0074] Fuel can be carbureted, or it can be injected in a throttle-body56 (seen in FIG. 16), or the fuel can be injected into the inlet streamof air, injected into a pre-combustion chamber (FIG. 21) or, injectedthrough the intake valve 16, or it may be injected directly into thecombustion chamber. If injected, it should be at or after the piston 22has reached point x and the intake valve is closed. The fuel can also beinjected later, similar to diesel operation, and can be injected at theusual point for diesel oil injection, perhaps into a pre-combustionchamber or directly into the combustion chamber or directly onto a glowplug. Some fuel can be injected after top dead center even continuouslyduring the first part of the expansion stroke for a mostly constantpressure combustion process.

[0075] Ignition can be by compression (which may be assisted by a glowplug), or by electric spark. Spark ignition can take place before topdead center, as normally done, at top dead center or after top deadcenter.

[0076] At an opportune time the air-fuel charge is ignited and the gasesexpand against the piston for the power (3rd) stroke. Near bottom deadcenter at the opportune time exhaust valve(s) 17 open and piston 22rises in the scavenging (4th) stroke, efficiently scavenging thecylinder by positive displacement, after which exhaust valve(s) 17closes.

[0077] This completes one cycle of the 4-stroke engine.

[0078] The Engine 100 ² of FIG. 2

[0079] Referring now to FIG. 2, there is shown a six cylinderreciprocating internal combustion engine 100 ² in which all of thecylinders 7 a-7 f (only two 7 a, 7 f of which are shown in a schematicdrawing) and associated pistons 22 a-22 f operate in a 4-stroke cycleand all power cylinders are used for producing power to a commoncrankshaft 20 via connecting rods 19 a-19 f, respectively. An ancillarycompressor 2 (herein depicted as a rotary compressor) supplies air whichhas been compressed, or allows delivery of air therethrough atatmospheric pressure, to manifolds 13 and 14 and to cylinders 7 a-7 fwhich cylinders operate in a 4-stroke cycle. A second ancillarycompressor 1 is used, selectively, to boost the air pressure tocompressor 2. Valves 3, 4, 5 and 6 and intercoolers 10, 11 and 12 areused, in the preferred embodiments, to control air charge density,weight, temperature and pressure. The intake valves 16 a-16 f are timedto control the compression ratio of the engine 100 ². The combustionchambers are sized to establish the expansion ratio of the engine.

[0080] The engine 100 ² shown in FIG. 2 is characterized by a moreextensive expansion process, a low compression ratio and the capabilityof producing a combustion charge varying in weight fromlighter-than-normal to heavier-than-normal, and capable of selectivelyproviding a mean effective cylinder pressure higher than can theconventional arrangement of normal engines but having similar or lowermaximum cylinder pressure in comparison to conventional engines. Anengine control module (ECM) 27 and variable valves 3, 4, 5 and 6 onconduits, as shown, provide a system for controlling the charge density,pressure, temperature, and the mean and peak pressure within thecylinder which allows greater fuel economy, production of greater torqueand power at low RPM, with low polluting emissions for both spark andcompression-ignited engines. In alternate embodiments, a variable valvetiming system can be used and, with a control system such as an enginecontrol module (ECM) 27, can control the time of opening, and the timeof closing of the intake valves 16 to further provide an improvedmanagement of conditions in the combustion chambers of cylinders 7 a-7 fof the engine 100 ² to allow for a flatter torque curve and higherpower, and with low levels of both fuel consumption and pollutingemissions.

Brief Description of Operation of the Engine 100 ² of FIG. 2

[0081] The engine 100 ² of this invention shown in FIG. 2 is a highefficiency engine that attains both high power and torque with low fuelconsumption and low polluting emissions. The new working cycle is anexternal compression type combustion cycle. In this cycle, part of theintake air (all of which is compressed in the power cylinders inconventional engines) is compressed, selectively, by at least oneancillary compressor 1, 2. The temperature rise during compression canbe suppressed by use of air coolers 10, 11, 12, which cool the intakeair, and by a shorter compression stroke.

[0082] One suggested, preferred method of operation of the new-cycleengine 100 ² is thus:

[0083] 1. Depending upon the power requirements of the engine (e.g.,differing load requirements), either intake air at atmospheric pressureor intake air that has been compressed by at least one ancillarycompressor and has had its temperature and pressure adjusted by bypasssystems and charge-air coolers, is drawn into the power cylinder 7 bythe intake stroke of piston 22.

[0084] 2. (a) After the intake stroke is complete, the intake valve 16(which can be single or multiple) is left open for a period of timeafter the piston 22 has passed bottom dead center which pumps part ofthe fresh air charge back into the intake manifold 13, 14. The intakevalve 16 is then closed at a point which action seals cylinder 7, thusestablising the compression ratio of the engine.

[0085]  (b) Alternatively, the intake valve 16 is closed early, duringthe intake stroke, before the piston 22 has reached bottom dead center.The trapped air charge is then expanded to the full volume of thecylinder 7 and compression of the charge starts when the piston 22reaches the point in the compression stroke at which the intake valve 16closed.

[0086] 3. (a) During the compression stroke of piston 22, at the pointthe intake valve 16 closed, either in 2(a) or 2(b) operation,compression begins, producing a small compression ratio. This makes itpossible to lessen the temperature rise during the compression stroke.

[0087]  (b) During light-load operation, such as in vehicle cruising orlight-load power generation, the shutter valves 3 and 5 are closed andthe air bypass valves (ABV) 4 and 6 to both compressors 1 and 2 are,preferably, opened so that the intake air is returned to the intakeconduits 110 and 103 of the compressors 2 and 1 without beingcompressed. During this time, the engine pistons 22 a-22 f are drawingin naturally aspirated air past the compressor(s). This reducescompressor drive work and further improves fuel economy.

[0088]  (c) When greater power is required, the charge density andpressure can be increased by closing air bypass valve (ABV) 4 causingcompressor 2 to raise the charge-air pressure and, in addition, byeither cutting in the second stage of compression by compressor 1 in thesame manner, that of closing air bypass valve ABV 6, or by increasingthe speed of compressor 2 or of both compressors. At the same time.shutter valves 3 and 5 would be opened to direct some or all of the aircharge through intercoolers 10, 11 and 12 in order to increasecharge-air density.

[0089] 4. Compression continues, fuel is added if not already present,the charge is ignited and combustion produces a large expansion of thegases against piston 22 producing great energy in either mode 3(a), (b)or (c). This energy produces a high mean effective cylinder pressure andis converted into high torque and power, especially in mode (c).

Detailed Description of Operation of the Engine 100 ² of FIG. 2

[0090] During the intake (1st) stroke of the piston 22 air flows throughair conduits 15 from the manifold 13 or 14 of air which air (dependingon power requirements) is either at atmospheric pressure or has beencompressed to a higher pressure by compressor 2 and/or compressor 1,through the intake valve 16 into the cylinder 7. During the intakestroke of piston 22 the intake valve 16 closes at point x sealingcylinder 7. From this point the air charge is expanded to the maximumvolume of the cylinder. Then during the compression (2nd) stroke, nocompression takes place until the piston 22 has returned to the point xwhere the intake valve 16 was closed during the intake stroke. (At pointx, the remaining displaced volume of the cylinder is divided by thevolume of the combustion chamber, to establish the compression ratio ofthe engine.) Alternatively, during the intake (1st) stroke of piston 22,the intake valve 16 is held open through the intake stroke and passedbottom dead center, and through part of the compression (2nd) stroke fora significant distance, 10% or, to perhaps 50% or more of thecompression stroke, thus pumping some of the charge-air back into intakemanifold 13 or 14, and the intake valve 16 then closes, sealing cylinder7, to establish a low compression ratio in the cylinders of the engine.At the time of closure of intake valve 16, the density, temperature andpressure of the cylinder 7 contents will be approximately the same asthat of the air charge in the intake manifolds 13 and 14.

[0091] During light-load operation, such as in vehicle cruising orlight-load power generation, the shutter valves 3 and 5 are closed andthe air bypass valves (ABV) 4 and 6 to both compressors 1 and 2 are,preferably opened so that the intake air is returned to the intakeconduits 110 and 103 of the compressors 2 and 1 without beingcompressed. During this time the engine pistons 22 a-22 f are drawing innaturally aspirated air past the compressor(s). This reduces compressordrive work and further improves fuel economy.

[0092] When medium torque and power is needed, such as highway drivingor medium electric power generation, preferably the shutter valves 3 and5 are closed and the air bypass valves (ABV) 4 and 6 are closed. Thiscauses the atmospheric pressure intake air to cease re-circulatingthrough the compressor 2 and 1 and both compressors begin to compressthe charge-air to a higher-than-atmospheric pressure, while the closedshutter valves 3 and 5 direct the charge-air through conduits 104, 110,111, and 121/122 bypassing the air coolers 10, 11 and 12, in FIG. 2,with the charge-air going directly to the manifold 13 and 14 and topower cylinders 7 a-7 f where the denser, but hot, charge increases themean effective cylinder pressure of the engine to create greater torqueand power.

[0093] When more power is needed, such as when rapid acceleration isneeded or for heavy-load electric power generation, preferably the airbypass valve (ABV) 4 is closed and the shutter valve 3 is opened. Thiscauses the compressor 2 to compress all of the air charge and shuttervalve 3 directs the air charge through conduits 112 and 1 13 and thecompressed charge-air is supplied to the manifolds 13 and 14 and to thecylinders 7 a-7 f via the charge coolers 11 and 12. For even greaterpower the shutter valve 5 is opened and the air bypass valve 6 is closedand compressor 1 begins a second stage of compression, and all of theair charge is now directed through intercoolers 10, 11 and 12 for highcharge density. The very dense cooled air charge when mixed with fueland ignited and expanded beyond the compression ratio of the engineproduces great torque and power.

[0094] The heavier the weight of the air charge and the denser thecharge, the earlier (or later) the intake valve can be closed toestablish a low compression ratio and retain power, and the less heatand pressure is developed during compression in the cylinder. In this4-stroke engine the intake charge can be boosted in pressure by as muchas 4-5 atmospheres and if the engine's compression ratio is low enough,say 4:1 to 8:1 (higher for diesel fuel), even spark-ignited there wouldbe no problem with detonation. The expansion ratio would still be verylarge, 14:1 would be a preferable expansion ratio for spark ignition,perhaps 19:1 for diesel operation.

[0095] The compression ratio is established by the displaced volume ofthe cylinder 7 remaining after point x has been reached in thecompression stroke (and intake valve 16 is closed) being divided by thevolume of the combustion chamber. The expansion ratio in all cases isgreater than the compression ratio. The expansion ratio is establishedby dividing the total displaced volume of the cylinder by the volume ofthe combustion chamber.

[0096] Fuel can be carbureted, or it can be injected in a throttle-body56 (seen in FIG. 16), or the fuel can be injected into the inlet streamof air, injected into a pre-combustion chamber as in FIG. 21 or,injected through the intake valve 16, or it may be injected directlyinto the combustion chamber. If injected, it should be at or after thepiston 22 has reached point x and the intake valve is closed. The fuelcan also be injected later and in the case of diesel operation can beinjected at the usual point for diesel oil injection, perhaps into apre-combustion chamber or directly into the combustion chamber ordirectly onto a glow plug.

[0097] At an opportune time the air-fuel charge is ignited and the gasesexpand against the piston for the power (3rd) stroke. Near bottom deadcenter at the opportune time exhaust valve(s) 17 open and piston 22rises in the scavenging (4th) stroke, efficiently scavenging thecylinder by positive displacement, after which the exhaust valve(s)closes.

[0098] This completes one cycle of the 4-stroke engine.

The Engine 100 ³ of FIG. 3

[0099] Referring now to FIG. 3, there is shown a six cylinderreciprocating internal combustion engine 100 ³ in which all of thecylinders 7 a-7 f (only one of which is shown in a sectional view) andassociated pistons 22 a-22 f operate in a 4-stroke cycle and all powercylinders are used for producing power to a common crankshaft 20 viaconnecting rods 19 a-19 f, respectively. An ancillary reciprocatingcompressor 1 and an ancillary rotary compressor 2 supply pressurizedcharge air which has been compressed, or allow deliver of airtherethrough at atmospheric pressure, to manifolds 13, 14 and tocylinders 7 a-7 f, which cylinders operate in a 4-stroke cycle. Valves3, 4, 5 and 6 and intercoolers 10, 11 and 12 are used, in the preferredembodiments, to control air charge density, weight, temperature andpressure. The intake valves 16 are timed to control the compressionratio of the engine 100 ³. The combustion chambers are sized toestablish the expansion ratio of the engine.

[0100] The engine 100 ³ shown in FIG. 3 is characterized by a moreextensive expansion process, a low compression ratio and the capabilityof producing a combustion charge varying in weight fromlighter-than-normal to heavier-than-normal, and capable of selectivelyproviding a mean effective cylinder pressure higher than can theconventional arrangement of normal engines but having similar or lowermaximum cylinder pressure in comparison to conventional engines. Anengine control module (ECM) 27 and variable valves 3, 4 and 6 onconduits, as shown, provide a system for controlling the charge density,pressure, temperature, and the mean and peak pressure within the powercylinder 7 which allows greater fuel economy, torque and power at lowRPM, with low polluting emissions for both spark and compression-ignitedengines. In alternate embodiments, a variable valve timing system can beused and, with a control system such as an engine control module (ECM)27, can control the time of opening and the time of closing of theintake valves 16 to further provide an improved management of conditionsin the combustion chambers of cylinders 7 a-7 f of the engine 100 ³ toallow for a flatter torque curve and high power and with low levels ofboth fuel consumption and polluting emissions.

Brief Description of Operation of the Engine 100 ³ of FIG. 3

[0101] The engine 100 ³ of this invention shown in FIG. 3 is a highefficiency engine that attains both high power and torque with low fuelconsumption and low polluting emissions. The new working cycle is anexternal compression type combustion cycle. In this cycle part of theintake air (all of which is compressed in the power cylinders inconventional engines) is selectively compressed by at least oneancillary compressor 1, 2. The temperature rise during compression canbe suppressed by use of air coolers 10, 11, 12, which cool the intakeair, and by a shorter compression stroke.

[0102] One suggested, preferred method of operation of the new-cycleengine 100 ³ is thus:

[0103] 1. Depending upon the power requirements of the engine (e.g.,differing load requirements), either intake air at atmospheric pressureor intake air that has been compressed by at least one ancillarycompressor and has had its temperature and pressure adjusted by bypasssystems and charge-air coolers, is drawn into the power cylinder 7 bythe intake stroke of piston 22.

[0104] 2. (a) After the intake stroke is complete the intake valve 16(which can be single or multiple, 16, 16′) is left open for a period oftime after the piston 22 has passed bottom dead center which pumps partof the fresh air charge back into the intake manifolds 13, 14. Theintake valve 16 is then closed at a point which seals cylinder 7, thusestablishing the compression ratio of the engine.

[0105]  (b) Alternatively, the intake valve 16 is closed early, duringthe intake stroke, before the piston 22 has reached bottom dead center.The trapped air charge is then expanded to the full volume of thecylinder 7 and compression of the charge starts when the piston 22reaches the point in the compression stroke at which the intake valve 16closed.

[0106] 3. (a) During the compression stroke of piston 22, at the pointthe intake valve 16 closed, either in 2(a) or 2(b) operation,compression begins, producing a small compression ratio. This makes itpossible to lessen the temperature rise during the compression stroke.

[0107]  (b) During light-load operation, such as in vehicle cruising orlight-load power generation, the shutter valves 3 and 5 are closed andthe air bypass valves (ABV) 4 and 6 on both compressors 1 and 2 are,preferably, opened so that the intake air is returned to the intakeconduits 110 and 8 of the compressors 1 and 2 without being compressed.During this time the engine pistons 22 a-22 f are drawing in naturallyaspirated air past the compressor(s). This reduces compressor drive workand further improves fuel economy.

[0108]  (c) When greater power is required, the charge density andpressure can be increased by closing air bypass valve (ABV) 4 causingcompressor 1 to raise the charge-air pressure and, in addition, byeither cutting in the second stage of compression by compressor 2, ifneeded, in the same manner, that of closing ABV valve 6, or byincreasing the speed of compressors 1 or 2, or both. At the same time,shutter valves 3 and 5 would direct some or all of the air chargethrough intercoolers 10, 11, and 12 in order to increase charge-airdensity.

[0109] 4. Compression continues, fuel is added if not already present,the charge is ignited and combustion produces a large expansion of thegases against piston 22 producing great energy in either mode 3(a), (b)or (c). This energy produces a high mean effective cylinder pressure andis converted into high torque and power, especially in mode (c).

Detailed Description of Operation of the Engine 100 ³ of FIG. 3

[0110] During the intake (1st) stroke of the piston 22 air flows throughair conduits 15 from the manifold 13 or 14 of air which air (dependingon power requirements) is either at atmospheric pressure or has beencompressed to a higher pressure by compressor 1 or 2 through the intakevalve 16 into the cylinder 7. During the intake stroke of piston 22 theintake valve 16 closes (at point x). From this point the cylindercontents are expanded to the maximum volume of the cylinder. Then duringthe compression (2nd) stroke, no compression takes place until thepiston 22 has returned to the point x where the intake valve 16 wasclosed, sealing the cylinder 7, during the intake stroke. (At point x,the remaining displaced volume of the cylinder is divided by the volumeof the combustion chamber, to establish the compression ratio of theengine.) Alternatively, during the intake (1st) stroke of piston 22, theintake valve 16 can be held open through the intake stroke passed bottomdead center, and through part of the compression (2nd) stroke for asignificant distance, 10% to perhaps 50% or more of the compressionstroke pumping some of the charge-air back into intake manifold, and theintake valve 16, 16′ then closes to establish a low compression ratio inthe cylinders of the engine.

[0111] During light-load operation, such as in vehicle cruising orlight-load power generation, the shutter valves 3 and 5 are closed andthe air bypass valves (ABV) 4 and 6 on both compressors 1 and 2 are,preferably, opened so that the intake air is returned to the intakeconduits 110 and 8 of the compressors 1 and 2 without being compressed.During this time the engine pistons 22 a-22 f are drawing in naturallyaspirated air past the compressor(s). This reduces compressor drive workand further improves fuel economy.

[0112] When medium torque and power is needed, such as highway drivingor medium electric power generation, preferably the shutter valve 3 tocompressor 1 is opened, the air bypass valve (ABV) 4 is closed and ABV 6remains open. This causes the atmospheric pressure intake air to ceasere-circulating through the compressor 1; and the compressor 1, alone,begins to compress the charge-air to a higher-than-atmospheric pressure,while the closed shutter valves 3 and 5 directs the charge-air throughconduits 104, 110, 111, and 121/122 bypassing the air coolers 10, 11 and12, in FIG. 3, with the charge-air going directly to the manifolds 13and 14 and to power cylinders 7 a-7 f where the denser heated chargeincreases the mean effective cylinder pressure of the engine to creategreater torque and power.

[0113] When more power is needed, such as when rapid acceleration isneeded or for heavy-load electric power generation, preferably the airbypass valves (ABV) 4 and 6 are closed and the shutter valves 3 and 5are opened on both compressors. This causes the compressors 1 and 2 tocompress all of the air charge and shutter valves 3 and 5 direct the aircharge away from conduit 8 and through the compressors 1 and 2, and thecompressed charge-air is then supplied through conduits 105, 106, 110,112, 113, 114 and 115 to the manifolds 13 and 14 and to the cylinders 7a-7 f via the charge coolers 10, 11 and 12. The very dense cooled aircharge when mixed with fuel and ignited and expanded beyond thecompression ratio of the engine produces great torque and power.

[0114] The heavier the weight of the air charge and the denser thecharge, the earlier in the intake stroke (or the later in thecompression stroke) the intake valve can be closed to establish a lowcompression ratio and retain power, and the less heat and pressure isdeveloped during compression in the cylinder. In this 4-stroke enginethe intake charge can be boosted in pressure by as much as 4-5atmospheres and if the compression ratio is low enough, say 4:1 to 8:1(higher for diesel fuel), even spark-ignited there would be no problemwith detonation. The expansion ratio would still be very large, 14:1would be a preferred expansion ratio for spark ignition, perhaps 19:1for diesel operation.

[0115] The compression ratio is established by the displaced volume ofthe cylinder 7 remaining after point x has been reached in thecompression stroke (and intake valve 16 is closed) being divided by thevolume of the combustion chamber. The expansion in all cases is greaterthan the compression ratio. The expansion ratio is established bydividing the total displaced volume of the cylinder by the volume of thecombustion chamber.

[0116] Fuel can be carbureted, or it can be injected in a throttle-body,or the fuel can be injected into the inlet stream of air, injected intoa pre-combustion chamber, FIG. 21, or, injected through the intake valve16, or it may be injected directly into the combustion chamber. Ifinjected, it should be at or after the piston 22 has reached point x andthe intake valve is closed. The fuel can also be injected later and inthe case of diesel operation can be injected at the usual point fordiesel oil injection, perhaps into a pre-combustion chamber or directlyinto the combustion chamber or directly onto a glow plug.

[0117] At an opportune time the air-fuel charge is ignited and the gasesexpand the piston 22 for the power (3rd) stroke. Near bottom dead centerat the opportune time exhaust valve(s) 17 open and piston 22 rises inthe scavenging (4th) stroke, efficiently scavenging the cylinder bypositive displacement, after which exhaust valve(s) 17 closes.

[0118] This completes one cycle of the 4-stroke engine.

The Engine 100 ⁴ of FIG. 4

[0119] Referring now to FIG. 4, there is shown a six cylinderreciprocating internal combustion engine 100 ⁴ having two atmosphericair intakes 8 and 9 and corresponding intake conduits 15-A, 15-B, inwhich all of the cylinders (only one (7) of which is shown in asectional view) 7 a-7 f and associated pistons 22 a-22 f operate in a4-stroke cycle and all power cylinders are used for producing power to acommon crankshaft 20 via connecting rods 19 a-19 f, respectively. Acompressor 2, in this figure a Lysholm type rotary compressor, is shownwhich, with air conduits as shown, supplies pressurized air to one ormore cylinder intake valves 16-A. An air inlet 8 and an ancillary airinlet 9 and inlet conduits 15-A, 15-B selectably supply air charge atatmospheric pressure or air which has been compressed to a higherpressure to separate intake valves 16-A and 16-B opening to the samecylinder 7 a-7 f (for example, shown here opening to cylinder 7 f).Intercoolers 10, 11 and 12 and control valves 3, 5 and 6 are used, inthe preferred embodiments, to control the air charge density, weight,temperature and pressure. The intake valves 16 a-B -16 f-B which receiveair through manifold 14-B and intake conduits 15 a-B to 15 f-B, aretimed to control the compression ratio of the engine 100 ⁴. Thecombustion chambers are sized to establish the expansion ratio of theengine. Because of noticeable similarities between the engine 100 ⁴ ofFIG. 4 and that of FIG. 7 (where the auxiliary air inlet 9 system hasbeen shown in phantom, for informational value), reference will be madeas deemed helpful to FIG. 7 for certain common components.

[0120] The engine 100 ⁴ shown in FIG. 4 is characterized by a moreextensive expansion process, a low compression ratio and capable ofproducing a combustion charge varying in weight from lighter-than-normalto heavier-than-normal and capable of selectively providing a meaneffective cylinder pressure higher than can the conventional arrangementin normal engines with similar or lower maximum cylinder pressure incomparison to conventional engines. Engine control module (ECM) 27(refer, for example to FIG. 7) and variable valves 3, 5, and 6 onconduits, as shown, provide a system for controlling the chargepressure, density, temperature, and mean and peak pressure within thecylinder which allows greater fuel economy, production of greater powerand torque at all RPM, with low polluting emissions for both spark andcompression ignited engines. In alternate embodiments, a variable valvetiming system with the ECM 27 can also control the time of opening andclosing of the intake valves 16-A and/or 16-B, to further provide animproved management of conditions in the combustion chambers to allowfor a flatter torque curve, and higher power, with low levels of bothfuel consumption and polluting emissions.

Brief Description of Operation of the Engine 100 ⁴ Shown in FIG. 4

[0121] The new cycle engine 100 ⁴ of FIG. 4 is a high efficiency enginethat attains both high power and torque, with low fuel consumption andlow polluting emissions. The new cycle is an external compression typecombustion cycle. In this cycle, part of the intake air (all of which iscompressed in the power cylinders in conventional engines) isselectively compressed by an ancillary compressor 2. The temperaturerise at the end of compression can be suppressed by use of air coolers10. 11, 12, which cool the intake air, by the late injection oftemperature-adjusted air. and by a shorter compression stroke.

[0122] During operation, a primary air charge is supplied to thecylinder 7 through intake valve 16-B at atmospheric pressure or airwhich has been increased by perhaps one-half to one atmosphere throughan ancillary air inlet 9 which can be carbureted. This charge can becompressed, fuel added if not present, ignited at the appropriate pointnear top dead center for the power stroke—providing high fuel economyand low polluting emissions.

[0123] When more power is desired, a secondary air charge originatingfrom air inlet 8 is. preferably, introduced into the power cylinder 7during the compression stroke by a second intake valve 16-A whichintroduces a higher pressure air charge after the first intake valve16-B has closed in order to increase the charge density when needed.After the secondary air charge has been injected, intake valve 16-Aquickly closes. The primary air charge may be boosted to a higherpressure by cutting in a second ancillary compressor, in series withcompressor 2, (see for example, compressor 1 in FIG. 7, where theprimary compressor to be used in the engine of FIG. 4 is the compressor2—shown in FIG. 4 and FIG. 7, for example, as a Lysholm rotary type)between air inlet 8 and manifold 13, 14, and can be intercooled. Thetemperature, pressure, amount and point of injection of the secondarycharge, if added, is adjusted to produce the desired results. An intakevalve disabler (there are several on the market, for example, EatonCorp. and Cadillac), in preferred embodiments, may be used to disableintake valve 16-A when light-load operation does not require a high meaneffective cylinder pressure. Alternatively, the air bypass valve (ABV) 6is opened to re-circulate the charge-air back through the compressor 2in order to relieve the compressor of compression work during light-loadoperation.

[0124] Alternatively, a one-way valve, one type of which is shown as 26in FIG. 6 can be utilized to provide a constant or a variable “pressureratio” in the cylinder 7, while improving swirl turbulence. In thisalternate method of operation the intake valve 16-A would close verylate and valve 26 would close only when the pressure in the cylinder 7nearly equates or exceeds the pressure in conduit 15-A. Thus, thepressure in conduit 15-A, controlled by compressor speed, along withvalves 3, 5 and 6 (and valve 4 in FIG. 7) would regulate the pressure,density, temperature and turbulence of the combustion process. Aspring-retracted disc type, metal or ceramic, or any other type ofautomatic valve could replace valve 26.

[0125] Another alternate method of providing a low compression ratio,with a large expansion ratio and reduced polluting emissions is thus:

[0126] The air pressure supplied to intake runner-conduit 15-A isproduced at an extremely high level, and intake valve 16-A is, inalternate embodiments, replaced by a fast-acting, more controllablevalve such as but not limited to a high speed solenoid valve (notshown), which valve is, preferably, either mechanically, electrically orvacuum operated under the control of an engine control module (ECM). Insuch an embodiment, a smaller, denser, temperature-adjusted,high-pressure charge, with or without accompanying fuel, can,selectively, be injected, tangentially oriented, much later in thecompression stroke, or even during the combustion process, in order toincrease charge density, to reduce peak and overall combustiontemperatures, and to create the desired charge swirl turbulence in thecombustion chamber(s).

[0127] One suggested, preferred method of operation of the new-cycleengine 100 ⁴ is thus:

[0128] 1. Depending upon the power requirements of the engine (e.g.,differing load requirements), either intake air at atmospheric pressureor intake air that has been compressed by one compressor (not shown) andhas had its temperature adjusted by bypass systems and charge-aircoolers (not shown) is drawn into the cylinder 7 (intake stroke) throughair inlet 9 manifold 14-B, intake conduits 15-B. and intake valves 16a-B-16 f-B by intake stroke of piston 22.

[0129] 2. (a) After the intake stroke is complete the intake valve 16-B(which can be single or multiple), is left open for a period of timeafter the piston 22 has passed bottom dead center, which pumps part ofthe fresh air charge back into the intake manifold 14-B.

[0130]  (b) Alternatively, the intake valve 16-B is closed early, duringthe intake stroke before the piston reaches bottom dead center. Thetrapped air charge is then expanded to the full volume of the cylinder7.

[0131] 3. (a) The compression (2nd) stroke now begins and, at the pointthe intake valve 16-B is closed to seal cylinder 7 in either 2(a) or2(b) operation. compression begins (for a small compression ratio). Thismakes it possible to lessen the temperature rise during the compressionstroke.

[0132]  (b) When greater power is required a secondary compressed,temperature-adjusted air charge is injected into the cylinder 7 byintake valve 16-A which opens and closes quickly during the compressionstroke at the point at which the intake valve 16-B which introduced theprimary air charge closes, or later in the stroke, to produce a moredense, temperature controlled charge in order to provide the torque andpower desired of the engine.

[0133]  (c) Alternatively, when greater power is required, the secondaryair charge can be increased in density and weight by causing shuttervalves 5 and 3 to direct all or part of the air charge through one ormore of intercoolers 10, 11 and 12 to increase the charge density and/orby increasing compressor speed or by cutting in a second stage ofauxiliary compression, the latter two actions thereby pumping in moreair on the backside. Alternatively, the timing of the closing of intakevalve 16-B on either the inlet or compression stroke can be alteredtemporarily to retain a larger charge, and at the same time the timingof intake valve 16-A can be temporarily altered to open and closeearlier during the compression stroke to provide a larger dense,temperature-adjusted air charge.

[0134] 4. Compression continues, fuel is added if not present, thecharge is ignited and combustion produces a large expansion of thecombusted gases against the piston 22 producing great energy in eithermode 3(a), (b), or (c). This energy is absorbed and turned into hightorque and power, especially in mode (c).

[0135] 5. Near bottom dead center of the piston, exhaust valves 17 a-17f, 17 a′-17 f open and the cylinder 7 is efficiently scavenged by the(4th) stroke of piston 22, after which valve(s) 17 close.

Detailed Description of the Operation of the Engine 100 ⁴ of FIG. 4

[0136] During the intake (1st) stroke of the piston 22 low pressure airflows through air conduit 15-B from the atmospheric air inlet 9 throughmanifold 14-B of air at atmospheric pressure or which has been boostedin pressure (or, alternatively, the low pressure air can be supplied bya pressure regulator valve 25 and conduit 15-B from compressed air line15-A as shown in FIG. 5), through an intake valve 16-B into the cylinder7. During the intake stroke of piston 22, the intake valve 16-B closes(point x). From this point the air charge in the cylinder is expanded tothe maximum volume of the cylinder. Then, during the compression (2nd)stroke, no compression of the charge takes place until the piston 22returns to point x where the inlet valve was closed. (At point x, theremaining displaced volume of the cylinder is divided by the volume ofthe combustion chamber, establishing the compression ratio of theengine.) At any point in the compression stroke of piston 29 at the timeor after the piston 22 reaches point x a second inlet valve 16-A is,selectively opened in order to inject a secondary pressurized air chargeat a temperature, density and pressure deemed advantageous to the engineload, torque demand, fuel economy and emissions characteristics desired.Alternatively, during the intake of charge-air by intake valve 16-B, theintake valve 16-B is held open past bottom dead center for a significantdistance, 10% to perhaps 50% or more of the compression stroke, thuspumping some of the charge back into the intake manifold 14-B, and thenclosed to establish a low compression ratio in the cylinder. During thecompression stroke, at or after the time intake valve 16-B is closed, asecondary charge of high pressure, temperature-adjusted air which hasbeen compressed by compressor 2 is, selectively, injected by a secondintake valve 16-A, which opens and closes quickly, into the samecylinder 7. Alternatively, when greater torque and power are needed, thedensity of the secondary charge-air is greatly increased by increasingthe speed of the primary compressor 2 or by cutting in another stage ofcompression, as in item 1, FIG. 7, and/or by routing the air chargethrough intercoolers.

[0137] For light-load operation a shut-off valve, or a valve disabler 31(such as shown in FIG. 7) on the high pressure intake valve 16-A,preferably, temporarily restrains the intake air, or holds the valveclosed. This would add to the fuel economy of the engine. Alternatively,during light-load operation the shutter valve 5 is closed and the airbypass valve ABV 6 is opened so that part or all of the air pumped bycompressor 2 would be returned to the inlet conduit of the compressor 2for a low, or no pressure boost. Therefore, when secondary intake valve16-A opens, the pressure of the air in conduit 15-A is approximately thesame as, or not much greater than that from the initial charge. In analternate embodiment, an ancillary automatic valve 26, FIG. 6, isarranged, as shown in FIG. 6, to prevent any back-flow of charge-airinto conduit 15-A if the cylinder pressure should exceed the pressure inconduit 15-A before intake valve 16-A closed during the compressionstroke of piston 22.

[0138] If an ancillary one-way valve (see valve 26 of FIG. 6) ispresent, the pressure ratio in cylinder 7 can be fully controlled byadjusting the pressure of the charge air passing through intake valve16-A. The pressure ratio can then be controlled by valves 3, 5, 6 and bycompressor speed and any throttle valve that may be present. In the useof valve 26, intake valve 16-A must be kept open until very late in thecompression stroke, perhaps until piston 22 nears or reaches top deadcenter.

[0139] Fuel can be carbureted in FIG. 4, FIG. 4-B, FIG. 5, FIG. 7 andFIG. 33, injected in a throttle body 56 (seen in FIG. 16), or the fuelcan be injected into the inlet stream of air, injected into apre-combustion chamber or, injected through intake valves 16-A, 16-B,(16-B only if 16-B does not remain open past bottom dead center), or itmay be injected directly into the combustion chamber at point x duringthe intake stroke, (during the intake stroke only if intake valve 16-Bcloses before bottom dead center), or at the time or after the piston 22has reached point x in the compression stroke. The fuel can be injectedwith or without accompanying air. In the case of diesel operation, fuelcan be injected at the usual point for diesel oil injection, perhapsinto a pre-combustion chamber or directly into the combustion chamber ordirectly onto a glow plug.

[0140] After the temperature-and-density-adjusting-air charge has beeninjected, if used, compression of the charge continues and with fuelpresent, is ignited at the opportune time for the expansion (3rd andpower) stroke. (The compression ratio is established by the displacedvolume of the cylinder remaining after point x has been reached on thecompression stroke, being divided by the volume of the combustionchamber. The expansion ratio is determined by dividing the cylinderstotal clearance volume by the volume of the combustion chamber.) Now thefuel-air charge is ignited and the power, (3rd) stroke of piston 22takes place as the combusted gases expand. Near bottom dead center ofthe power stroke the exhaust valves(s) 17, 17′ opens and the cylinder 7is efficiently scavenged on the fourth piston stroke by positivedisplacement, after which exhaust valve(s) 17 closes.

[0141] This completes one cycle of the 4-stroke engine.

[0142] It can be seen that the later the point in the compression strokethat point x is reached (the earlier or later the inlet valve isclosed), the lower is the compression ratio of the engine and the lessthe charge is heated during compression. It can also be seen that thelater the temperature-density-adjusting charge is introduced, the lesswork will be required of the engine to compress the charge, the laterpart of which has received some compression already by an ancillarycompressor 2.

[0143] The Engine 100 ^(4-B) of FIG. 4-B

[0144] Referring now to FIG. 4-B there is shown a six cylinder 4-strokeinternal combustion engine similar in construction to the engine of FIG.4 with the exception that the engine of FIG. 4-B is so constructed andarranged that compressor 2 receives charge-air from manifold 14-Bthrough opening 8-B (shown in FIG. 7) and conduit 8 which air entersthrough common air intake duct 9. Intake runners 15 a-C to 15 f-Cdistributes the atmospheric pressure air to the intake valves 16-B ofeach power cylinder. This arrangement allows the provision of air tointake valves 16-A and 16-B at different pressure levels since thecharge-air from conduits 15-A is selectively pressurized by compressor2. The operation of the engine of FIG. 4-B is the same as that of theengine of FIG. 4.

The Engine 100 ⁵ of FIG. 5

[0145] Referring now to FIG. 5. there is shown a six cylinder 4-strokeinternal combustion engine 100 ⁵ similar to the engines 100 ⁴ of FIG. 4and engine 100 ^(4-B) of FIG. 4-B with the exception that there areshown alternative ways that the dual atmospheric air inlets can beeliminated, preferably by providing the low pressure charge-air tointake valves 16-B by way of conduits 15 a-D to 15 f-D all leading fromthe common air inlet conduit 8, or from an optional air manifold 35-M,situated between inlet conduit 8 and the inlet of conduits 15 a-D to 15f-D, which manifold would also supply air to compressor 2 throughconduit 8-A. Providing the low pressure charge-air to intake valve 16-Bby way of conduit 15-D, or by conduit 15-B (shown in phantom) wouldeliminate a second air filter and air induction system and would workwell with either the first system described which involves closing theprimary intake valve 16-B during the intake stroke of the piston 22 oralternatively closing the primary intake valve 16-B during the 2nd orcompression stroke. Alternatively, as shown, the low pressure charge-aircan be supplied by placing a pressure-dropping valve 25 in conduit 15-Brouted for leading from the pressurized air conduit 15 (15-A) to the lowpressure cylinder inlet valve 16-B in order to drop the inducted airpressure down to the level that could be controlled by the system ofcompression ratio adjustment described herein, preferably down to 1.5 to2.0 atmospheres (absolute pressure which is a boost of 0.5 to 1.0atmosphere) and perhaps down to atmospheric pressure.

[0146] The operation of the engine 100 ⁵ of FIG. 5 would be the same asthe operation of the engine 100 ⁴ of FIG. 4 although the low pressureprimary air supply is supplied differently. Because of noticeablesimilarities between the engine 100 ⁵ of FIG. 5 and that of FIG. 7,reference will be made as deemed helpful to FIG. 7 for certain commoncomponents.

[0147] During light-load operation of this 4-stroke cycle engine (FIG.4, FIG. 4-B and FIG. 5) such as vehicle cruising or light-load powergeneration, the secondary air charge is, alternatively, eliminated bydisabling high pressure intake valve 16-A temporarily (there are severalvalve disabling systems available. e.g., Eton. Cadillac. etc.) or aircan be shut off to intake valve 16-A and the engine still producegreater fuel economy and power than do conventional engines.

[0148] Alternatively and preferably, during light load operation such asvehicle cruising, the compressor 2 can be relieved of any compressionwork by closing the shutter valve 5 and opening the air bypass valve 6which circulates the air pumped back into the compressor 2 and then theair in intake conduits 15 -A and 15-B or 15-D are approximately equal.Therefore, no supercharging takes place during this time. In oneembodiment, automatic valve 26, FIG. 6, prevents back-flow of air duringthe compression stroke if compression pressure in the cylinderapproximates or exceeds the pressure in conduit 15-A before the intakevalve 16-A closes.

[0149] For increased power the secondary air charge may be increased byshutter valves 3 and 5 being preferably opened to direct the air chargeto intercoolers 10, 11 and 12, which makes the charge denser and/or byincreasing the speed of compressor 2 or by adding a second stage ofpre-compression by compressor 1 in FIG. 7, the latter two actionsthereby pumping in more air on the backside. There is shown in FIG. 7that the primary compressor 2 is a Lysholm rotary type and a secondarycompressor 1 is a rotary compressor of the turbo type, although any typeof compressors can be used in the engines of this invention.

[0150] Referring now to FIG. 6 there is shown the same 4-stroke engineand a similar operating system as described for the engines of FIG. 4,FIG. 4-B, FIG. 5, FIG. 7 and FIG. 33, except that the engine of FIG. 6has an added feature in that the secondary intake valve 16-A has anauxiliary valve 26 which is automatic to prevent charge-air back-flowfrom cylinder 7. This feature will prevent any back-flow from occurringduring the compression stroke of the engine of this invention. Thisfeature can also be used to establish the pressure ratio of the engine,either variable or constant. If secondary charge air is being receivedthrough intake valve 16-A, the intake valve 16-A can be kept open duringthe compression stroke to near top dead center of piston 22, sinceautomatic valve 26 closes at such time the pressure in cylinder 7approximates the pressure in intake runner conduit 15A. Therefore, thepressure differential between cylinder 7 and intake runner 15-A willallow closure of automatic valve 26, even though intake valve 16-A maystill be open, allowing the pressure ratio of cylinder 7 to becontrolled by the pressure of any charge air coming through intakerunner 15-A, which in turn is controlled by valves 3, 5, and 6 andcompressor speed and perhaps a throttle valve, if present, for engineshaving a single stage of pre-compression. Valves 3, 4, 5 and 6 andcompressor speed and any throttle valve present would control thepressure ratios for engines having two stages of pre-compression. If nocharge is passing from intake valve 16-A, automatic valve 26 will bealready closed and the pressure ratio is set by the compression ratio ofthe engine and the density and temperature of the charge received bycylinder 7 through intake valve 16-B. The compression ratio is still setby the point in cylinder 7 that the primary intake valve 16-B is closed.The pressure ratio is set by the density and temperature of the airpresent in cylinder 7 whether it enters through valve 16-B, 16-A orboth, and by the compression ratio.

[0151] Any type of automatic valve can be used for item 26, perhaps aspring-retracted disc type which can be made of metal or ceramics.

The Engine 100 ⁷ of FIG. 7

[0152] Referring now to FIG. 7, there is shown a schematic drawing of asix cylinder engine 100′ operating in a 4-stroke cycle. The engine issimilar in structure and operation to the 4-stroke engine of FIG. 4,FIG. 4-B and FIG. 5 and shows alternative air induction systemsutilizing air intake 9 (in phantom) or air intake 8′, or both. FIG. 7also shows three intercoolers 10, 11 and 12 and dual manifolds 13 and 14plus alternative intake manifold 14-B. The need for dual atmospheric airintake (8′ and 9 in FIG. 7) can be eliminated by providing air from port8-B of manifold 14-B directly to air intake conduit 8′ shownschematically, in FIG. 7.

[0153] One alternate air induction system shown in FIG. 7 suppliesunpressurized charge-air to intake valve 16-B of the engine of FIG. 4-Band of FIG. 7 by providing atmospheric pressure air to the intakerunners 15 a-C to 15 f-C leading from manifold 14-B in FIG. 4-B and FIG.7 which receives atmospheric air through induction port 9, and thendistributes the unpressurized air to intake valves 16-B of each powercylinder. Then, high pressure air enters through intake valve 16-A afterpiston 22 has reached point x during the compression stroke (the pointin which intake valve 16-B closes and compression begins). Intake valve16-A then closes, compression continues, fuel is added if not presentand the charge is ignited near top dead center (TDC) and the power (3rd)stroke occurs.

[0154] A second alternate air induction system shown in FIG. 7 supplieslow pressure intake air as also shown in FIG. 5 of alternativelyreceiving air from high pressure conduit 15-A through conduit 15-B withthe optional pressure reducing valve 25, (shown in phantom in FIG. 5 andFIG. 7). The secondary high pressure air charge is injected by intakevalve 16-A at the same time or later that the piston 22 reaches thepoint at which the intake valve 16-B closes and compression begins.Intake valve 16-A then quickly closes, compression continues, fuel isadded if not present and the charge is ignited at the appropriate placefor the power (3rd) stroke.

[0155] A third alternate and preferred air induction system shown inFIG. 7 supplies the primary air charge to intake valve 16-B as follows:Charge-air which has been pressurized to a low pressure by compressor 1,perhaps from 0.3 Bar to as much as 2 Bar or more, can selectively (andintermittently or continuously) be supplied to low pressure intakevalves 16-B of the engine of FIG. 7 by way of conduit 32 leading fromconduit 110 to the intake valves (16 a-B through 16 f-B) which conduitreceives charge-air at atmospheric pressure or which has beenpressurized and in any case has had its temperature optimized, allcontrolled by compressor 1 and intercooler 10 with the charge-air pathsbeing controlled by valves 5 and 6 with the corresponding conduits. Inthis case the valve 33 is optional. After cylinder 7 has been chargedand the compression ratio established by the closing of intake valve16-B during the first or second stroke of piston 22, the high pressureintake valve 16-A opens on the compression stroke at the point whichvalve 16-B closes, to inject the dense, temperature adjusted air chargeand then it closes, as compression continues and near top dead center,fuel being present, the charge is ignited and the power (3rd) strokeoccurs. The use of this system also eliminates the need for dualatmosphere air intakes.

[0156] A fourth alternate air induction system shown in FIG. 7 suppliesthe primary charge-air to the low pressure intake valves 16-B by havingcharge-air coming selectively from intake system 9, manifold 14-B andintake runners 15-C (show n in phantom) or from conduit 32 which woulddirect air to power cylinder 7 at whatever level of pressure andtemperature was needed at any particular time. With this arrangement,opening valve 33 at such a time that compressor 1 was compressing thecharge passing through it would have the effect of increasing thedensity of the primary charge-air which in this case could also have itstemperature as well as it pressure adjusted by compressor 1 and controlvalves 5 and 6. A one-way valve 34 would prevent the higher pressure airescaping through conduit 15-C. When less power was needed compressor 1could be “waste gated” by opening, partially or completely control valve6 and closing shutter valve 5. Alternatively, valve 33 could be closedby the engine control module (ECM) and the primary charge-air would bedrawn into cylinder 7 at atmospheric pressure through intake duct 9(shown in phantom). The piston 22 now begins its second stroke, theintake valve 16-B now closes, if not closed on the intake stroke, toestablish the compression ratio and in all cases the heavy secondarycharge enters through valve 16-A which opens at the time, or after,piston 22 has reached the point where intake valve 16-B had closed,valve 16-A then quickly closes, compression continues and the charge isignited near top dead center and the power (3rd) stroke occurs.

[0157] With this fourth alternate air induction system the low pressureintake valve 16-B can (a) receive charge-air at atmospheric pressure or(b) can receive charge-air which has been compressed and cooled throughconduit 32 or conduit 15-B. The high pressure intake valve 16-A (whichopens at the time, or later, at which compression begins) can receivecharge-air which (a) has been compressed and cooled in a single stage bycompressor 1 or compressor 2, (b) has been compressed and cooled in twostages or more to a very high density or (c) which has had itstemperature and pressure adjusted by control valves 5 and 6, all inorder to provide better management of combustion characteristics inregard to power, torque and fuel economy requirements and in regard toemissions control. By incorporating an optional one-way valve (see valve26 shown in FIG. 6), the engines of FIG. 4, FIG. 4-B, FIG. 5 and FIG. 7could have either a constant or a variable pressure ratio, the chargedensity, pressure, temperature and turbulence and the time of closing ofvalve 26 being controlled by valves 3, 5 and 6 and by compressor speedand by any throttle valve present in engines having one stage ofpre-compression, and by the addition of valve 4, in engines having twostages of pre-compression. In either case the intake valve 16-A shouldbe held open very late in the compression stroke, perhaps to near topdead center of piston 22.

[0158] One advantage to compressing the charge-air going to the lowpressure intake valve 16-B in addition to highly compressing thesecondary air charge is that during much of the duty cycle of suchengines the charge density could be dramatically increased while keepingpeak pressures and temperatures loss for high mean effective cylinderpressure. This system could provide all power necessary for vehiculartravel in hilly country with perhaps the high pressure intake valves16-A being deactivated by a valve deactivator indicated by 31 in FIG. 7,or by compressor 2 and/or compressor 1 being partially or whollybypassed by control valves 3 and 4 and/or control valves 5 and 6 to varythe pressure and temperature going into manifolds 13 and 14 and then tointake valves 16-A. For utmost power, the valve deactivators could beturned off or eliminated.

[0159] Also shown in FIG. 7 is a suggested engine control systemconsisting of an engine control module (ECM) 27, two shutter valves 3and 5, two air bypass valves 4 and 6, the optional pressure reducingvalves 25 (25 a-25 f) on air conduits 15-B (15 a-B-15 f-B), and a schemeof controlling the pressure, temperature and density by controlling airbypass valves 4 and 6 and shutter valves 3 and 5. As illustrated, airbypass valve 4 is closed to allow compressor 2 to fully compress thecharge and shutter valve 3 is slightly open allowing part of the air toflow uncooled (hollow arrows) and some of the air cooled (solid arrows)to the manifolds 13 and 14, all of which could be controlled by the ECM27 in order to provide an air charge at optimum density, temperature andpressure. The hollow arrow 4-A in conduit 120 shows how ABV 4 can bepartially opened to allow some of the air to bypass and return tocompressor 2 in order to finely adjust the pressure of the secondary aircharge that is injected to adjust the charge density and temperature.Alternatively, all of the air charge can be directed through theintercoolers 10, 11 and 12 or through bypass conduits 121 and 122, tothe manifolds 13 and 14.

[0160] For high power with a low compression ratio and low pollutingemissions, the air bypass valves (ABV) 4 and 6 are closed and theshutter valves 3 and 5 would be opened so that the compressors 2 and 1raise the pressure of the air charge which is directed by shutter valves3 and 5 through the intercoolers for maximum density. During the intakestroke the low pressure intake valve 16-B opens, piston 22 sucks in lowpressure air, the intake valve 16-B closes before bottom dead center orafter bottom dead center during the compression stroke. During thecompression stroke, at the point the intake valve 16-B closed or later,intake valve 16-A opens to inject the secondary, dense, cooled aircharge and then closes. Compression continues for a low compressionratio. Fuel is added, if not present, and the charge is ignited at theappropriate point near top dead center, (ignition can be before, at, orafter top dead center) for the power (3rd) stroke with a large expansionratio with high torque, then exhaust valve(s) 17 open and the scavenging(4th) stroke occurs, after which exhaust valve(s) 17 closes.

[0161] In these designs, fuel can be carbureted, throttle body injected,port injected, injected into the cylinder and can be introduced at anypoint between the air intake and the piston crown. The fuel air mixturecan be stratified, or from a stoichiometric to a very lean mixture forspark ignition, to a very rich mixture for diesel operation. The enginepower can be controlled by fuel metering alone or the air supply can beproperly adjusted to the proper fuel-air ratio by a throttle valve orcan be “metered” by control valves 4 and 6 when using two stages ofpre-compression and by control valve 4 when using a single stage ofpre-compression.

[0162] In any of the engines of this invention, the problem common tonormal engines of incomplete mixing of fuel, air and residual gas, withconsequent variation in conditions at the ignition point is minimizedand in some cases eliminated by the late air charge injection at highvelocity. This problem, hereby addressed by the present invention, isextreme in current engines when gaseous fuel is injected directly intothe cylinder where the spark may occur in mixtures of varying fuel-airratios, hence with various rates of flame development.

[0163] (Concerning the importance of finding a solution to thisparticular problem, engine researchers at Massachusetts Institute ofTechnology state “The elimination of cycle-to-cycle variation in thecombustion process would be an important contribution to improved[engine] performance If all cycles were alike and equal to the averagecycle, maximum cylinder pressures would be lower, efficiency would begreater, and most of all, the detonation limit would be higher, thusallowing appreciable increase in efficiency and/or mean effectivecylinder pressure with a given fuel.”)

[0164] The cyclic variation spoken of is minimized and, potentially,eliminated in the engine of each of the embodiments (includingtwo-stroke embodiments and four-stroke embodiments) of the currentinvention by the significant swirl turbulence produced by the injectionof high-pressure air. In addition, in any of the engines of thisinvention the swirl turbulence can be oriented tangentially to thecylinder wall by shrouding the inlet valve 16, and especially valve16-A, or by the use of a one-way valve (such as valve 26 in FIG. 6 andFIG. 10). Even engines that receive an air charge during the intakestroke of the piston using a shrouded intake valve have a tendency toreduce unwanted cyclic variation and have a decrease in octanerequirement and an increase in knock-limited indicated mean effective(cylinder) pressure (klimep). The engine of the present invention, byinjecting the charge-air, especially through a shrouded valve during thecompression stroke, creates a much greater swirl turbulence to furthereliminate unwanted cycle-to-cycle variation for cleaner, more completecombustion of the fuel.

[0165] The intake valve can rotate during operation and still have aflow tangential to the cylinder wall by using a conventional poppetvalve and having the side of the valve head which is opposite thedesired direction of the air flow being shrouded as it opens by athickened section of the face of the engine's head forming a crescentshaped collar or projection to direct the air flow in the desireddirection while the valve is open.

[0166] In the diesel combustion system, the better mixing process of thepresent invention allows much richer fuel-air ratios for greatersmoke-limited power, and smoke and particulates are virtually eliminatedto an extremely rich fuel-air ratio.

[0167] The swirl turbulence produced by high pressure charge injectionduring the compression stroke is not dampened by the compression strokeand the later the charge is injected, the smaller the volume of chargerequired to produce the desired swirl turbulence. In any reciprocatinginternal combustion engine operating in accordance with the method ofthe present invention, a very high pressure, temperature-controlled aircharge can, selectively, be injected tangentially oriented, very late inthe compression stroke, for example, just prior to, during or with fuelinjection and, with extremely high pressures, even during the combustionprocess.

[0168] Since the secondary air charge in the engine of FIG. 4 throughFIG. 7, FIG. 9, FIG. 9-B and FIG. 15 through FIG. 20 is compressible toan extremely high level of pressure, the intake valve 16-A is, inalternate embodiments, replaced by a more controllable and fast-actingvalve, such as, but not limited to, a high-speed solenoid valve (notshown). This valve is, preferably, operated either mechanically,electrically or by vacuum and is, preferably, controlled by an enginecontrol module (ECM) as illustrated in FIG. 7, FIG. 9-B, FIG. 15 throughFIG. 20 and FIG. 33. In this system the secondary air charge can,selectively, be injected very late in the compression stroke of piston22 in order to increase charge density, and swirl turbulence, and toreduce peak and overall combustion temperatures and to lessen theproduction of polluting emissions. The injection could be performed in atangentially oriented fashion. This would greatly increase swirlturbulence and prevent undesirable cyclic variations which are common innormal engines and most troubling in gaseous or diesel fueled engines.

[0169] The use of this s stem should result in lower maximum cylinderpressures and temperatures. Efficiency should be greater and thedetonation limit higher thus allowing an appreciable increase inefficiency and mean effective cylinder pressure with a given fuel. Allof the engines of this invention operate with a more complete expansionprocess as compared to the typical prior art engines, thereby providingfurther improvements in efficiency and emissions characteristics.

[0170] In accordance with the present invention, the 4-stroke engines ofthe present invention (for example, FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG.4-B, FIG. 5, FIG. 7 and FIG. 33) are designed, as are the 2-strokeengines of the present invention (for example, FIGS. 8-11, 25 and 33),to use an expansion ratio larger than the compression ratio. In order toaccomplish this result, the expansion ratio is set by selecting theappropriate combustion-chamber volume and the compression ratio isreduced below this value by very early or very late closing of the inletvalve.

The Engine 100 ⁸ of FIG. 8

[0171] Referring now to FIG. 8, there is shown a six cylinderreciprocating internal combustion engine 100 ⁸ for gasoline, diesel,alcohol, natural gas, hydrogen or hybrid dual-fuel operation and havingsix cylinders 7 a-7 f (only one, 7 f, is shown in a sectional view) inwhich the pistons 22 a-22 f are arranged to reciprocate. Anothercylinder is indicated only by the presence of the lower end of thecylinder liner 7 a. A cut-a-way view shows a double-acting compressorcylinder 1. Pistons 22 a-22 f are connected to a common crankshaft 20 ina conventional manner by means of connecting rods 19 a-19 f,respectively. The engine 100 ⁸ of FIG. 8 is adapted to operate in a2-stroke cycle so as to produce six power strokes per revolution of thecrankshaft 20. To this end compressor 1 takes in an air charge atatmospheric pressure, (or alternatively an air charge which previouslyhad been subjected to compression to a higher pressure via an admissioncontrol valve 6 through an intake conduit 102, leading from compressor 2by way of bypass control valve 6 and shutter valve 5 and bypass conduit104 or through the intercooler 10). During operation of the engine ofFIG. 8, the air charge is compressed within the compressor 1 by itsassociated piston 131, and the compressed charge is forced through anoutlet into a high-pressure transfer conduit 109 which leads to bypassvalve 3 which is constructed and arranged to channel the compressedcharge through intercoolers 11 and 12 or through bypass conduit 111 inresponse to signals from the engine control module (ECM) 27. This moduledirects the degree of compression, the amount and the direction of theflow of the compressed charge through the intercooler and/or the bypassconduit into manifolds 13 and 14. Manifolds 13 and 14 are constructedand arranged to distribute the compressed charge by means of branchintake conduits 15 a-15 f and to inlet valves 16 and 16′, and to theremaining five power cylinders. Alternatively, an ancillary compressor 2receives atmospheric air through inlet opening 8, pre-compresses the aircharge into conduit 101 leading to control valve 5 which in response tosignals from ECM 27 will direct the compressed charge throughintercooler 10 or bypass conduit 104 to compressor 1. The ECM 27 canalso control valves 4 and 6 to direct part or all of the charge passingthrough compressors 1 and 2 back through conduits 120 and 103 in orderto adjust the amount of compression of compressors 1 and 2 ranging ineither or both compressors from full compression to no compression, thusduring light-load operation either compressor 1 or compressor 2 couldsupply the needed compressed air to the cylinders.

[0172] The Engine 100 ⁸ of FIG. 8 has camshafts 21 which are arranged tobe driven at the same speed as the crankshaft in order to supply oneworking stroke per revolution for the power pistons. The reciprocatingcompressor can have one or more double-acting cylinders one is pictured1 and can have more than one stage of compression, and the crankshaft 20would supply two working strokes per revolution, for one or morecompressors, as described hereinafter. The reciprocating compressorcould alternatively be driven by a short crankshaft which would berotated by a step-up gear on the main crankshaft driving a smaller gearon the ancillary crankshaft. The ancillary rotary compressor 2 could bedriven by V-pulley operated by a ribbed V-belt and could have a step-upgear between the V-pulley and the compressor drive shaft. The rotarycompressor 2 could also have a variable speed drive as in some aircraftengines.

Description of the Operation of the Engine 100 ⁸ of FIG. 8.

[0173] Charge-air is induced into the inlet opening 8 of compressor 2,from there it passes through the compressor 2 where the charge is theninducted into conduit 101 to shutter valve 5 where the charge isdirected either through intercooler 10 or through air bypass valve 6where a portion or all of the charge can be directed back through thecompressor 2 where the charge is re-circulated without compression, orvalve 6 can direct the air charge into the inlet of compressor 1 wherethe air charge is pumped out the outlet duct of compressor 1 which leadsto shutter valve 3 where the charge is directed either throughintercoolers 11 and 12 or through air bypass valve 4 or a portionthrough both, leading to manifolds 13 and 14 which distribute thecharge-air to the intake valves 16 and to the intake valve of each powercylinder 7 of the engine 100 ⁸. (Bypass valve 4 can direct part or allof the air charge to manifolds 13 and 14, or can recirculate part or allof the air charge through conduit 120 back to conduit 106 and into theinlet of compressor 1.) The engine control module (ECM) 27 controlsvalves 3, 4, 5, and 6, in order to adjust the pressure, temperature anddensity of the charge that is inducted into the engine's combustionchambers 130. The same ECM 27 can control a variable-valve-happeningcontrol system to adjust the time of opening and closing of the inletvalves 16 and exhaust valves 17 of the power cylinders in relationshipto the angle of rotation of crankshaft 20, in order to adjust thecompression ratio and charge density of the engine for optimumperformance in regard to power, torque, fuel economy and characteristicsof fuel being supplied.

[0174] The operation of the power cylinder 7 is in this manner:

Alternate Method 1

[0175] Near the end of the power stroke in cylinder 7, the exhaustvalve(s) 17, 17′ open and with the exhaust valve still open, the piston22 begins the second or exhaust stroke. During the exhaust stroke,perhaps as early as 70° to 60° before top dead center the exhaust valves17, 17′ close. At the point the exhaust valves are closed thecompression ratio is established, the intake valves 16, 16′ are openedat that point or later in the compression stroke, the compressed airand/or air-fuel charge is injected into the combustion chamber 130 ofthe power cylinder 7, intake valve 16. 16′ closes at perhaps 60° beforetop dead center, with the swirl and squish turbulence accompanying thehigh-pressure air injection, the piston 22 continues towards the end ofits stroke thus compressing the charge producing a very low compressionratio, which can be as low as 2:1. If fuel is not already present as amixture, fuel is injected into the incoming air stream or it is injectedinto a pre-combustion chamber or directly into the combustion chamberafter closure of he intake valve. The fuel can be injected into themidst of the charge swirl for a stratified charge combustion process, orit can be injected onto a glow plug if diesel fuel is to be ignited. Thefuel-air mix is ignited by compression or spark, the latter at theopportune time for greatest efficiency and/or power. Generally, the fuelwould be injected and ignited before top dead center of the piston. Thefuel can be injected later and perhaps continuously during the earlypart of the expansion stroke for a mostly constant-pressure combustionprocess and especially for diesel fuel. The fuel air mixture is ignitedpreferably before the piston reaches top dead center and the combustedcharge expands against the piston as it moves toward bottom dead center.At near bottom dead center of the piston stroke, the exhaust valve(s) isopened and the exhausted mixture is scavenged by positive displacementby the piston 22 during the scavenging stroke. If the intake valve 16,16′ is opened earlier some valve overlap with the exhaust valve may berequired for scavenging. If the intake valves 16, 16′ are opened late novalve overlap would be needed, exhaust valve(s) 17, 17′ closing atapproximately the same time that intake valve(s) 16, 16′ open. Theexpansion ratio of the engine could be about 19:1, for diesel fuel, 14:1for gaseous fuel or gasoline, which expansion ratio is established bydividing the cylinder displacement volume by the volume of thecombustion chamber.

Alternate Operation Method 2

[0176] Near the end of the power stroke in cylinder 7 the exhaustvalve(s) 17, 17′ open, and with exhaust valve 17, 17′ still open, beginsits second or scavenging charging stroke. At a point near mid-stroke,(e.g., about 90° before top dead center,) the exhaust valve 17, 17′still being open, the intake valve opens with a small valve overlap toadmit high pressure scavenging and charging air. One or more intakevalves 16 can be recessed, as in item 30 in FIG. 11, in order to directthe first inlet air down and along the cylinder 7 wall in order toloop-scavenge the cylinder during the very small overlap of valves 16,16′ and 17, 17′. The exhaust valve 17, 17′ remains open to the point atwhich compression should begin and then receives the air charge as itcloses, intake valve(s) 16, 16′ closing soon after, with the cylinderadequately scavenged and charged with temperature-adjusted fresh air nowat high pressure. The piston 22 continues its stroke to compress thecharge producing a low compression ratio, ideally 13:1 to 4:1, dependingon the type of fuel used. The compression ratio is established by thepoint in the stroke of piston 22 in which the exhaust valve(s) 17, 17′closes, and is calculated when the remaining displaced volume of thecylinder is divided by the volume of the combustion chamber.

[0177] As piston 22 continues to rise from point x, where the exhaustvalve closes establishing the compression ratio, and where compressionof the charge started, the pressure starts to rise at the same point.The dense cooled air charge with the short compression stroke willproduce a low compression ratio with a very heavy charge, with lowmaximum cylinder pressure but with high effective mean cylinder pressurefor great torque and power.

[0178] The pressure ratio will be established by the density, pressureand temperature of the incoming charge, the length of time inletvalve(s) 16, 16′ are open and the point the exhaust valve(s) 1 7, 17′closes. The later the exhaust valves 17, 17′ close, the less thecharge-air expands after injection, the less work is required tocompress the charge and the less overlap of inlet and exhaust valve isrequired and the lower is the compression ratio.

[0179] At some point, perhaps as early as 150-120 degrees before pistontop dead center position, cylinder 7 would be adequately scavenged andthe exhaust valve 17, 17′ could be closed before, or no later than, thetime the intake valves 16, 16′ are opened to admit, in this case, theentire air charge, most of the exhausted gases having been displaced byscavenging. (In some cases some residual exhaust gases are beneficialand experiments will show at what point both intake and exhaust valvescan be closed without any overlap.) In this instance the “effective”compression ratio could be as low as 3:1 or even 2:1, again producinglow maximum cylinder pressure and temperature but with high meaneffective pressure. Fuel can be injected as early as at the point theexhaust valve closes and can be as early as about 150°-120° before theend of the compression stroke. The fuel-air mixture is ignited before,at, or after, top dead center and the expansion (2nd) stroke takesplace. The expansion ratio is established by dividing the cylinder'sdisplaced volume by the combustion chamber volume and could be about19:1 for diesel applications, and 14:1 for gasoline or gaseous fuels.

[0180] An engine control module (ECM) 27 can manage temperatures anddensities of the charge being introduced into the cylinder 7 orcombustion chamber 130 and the timing of the inlet into the combustionchamber and can thus adjust charge densities, turbulence, temperaturesand pressures providing a means of restraining peak temperatures andpressures yet with a mean effective cylinder pressure higher than in anormal engine, when needed, and further providing for lower levels ofunwanted polluting emissions.

[0181] A suggested light-load, fuel efficient operation system asindicated on line B(bp) in FIG. 13, would be thus: A nominal compressionratio of 13:1 could be chosen, with an expansion ratio of 19:1. Thelatter would establish the volume of the combustion chamber, the formerwould establish the maximum charge pressure (not maximum cylinderpressure), about 530 psi when compressed adiabatically. The ECM 27 wouldsignal shutter valves 5 and air bypass control valve 6 to re-circulatethe air being pumped through compressor 2, back through the compressor 2without being compressed or for any type compressor, open a waste-gatevalve to bypass the compressor. Shutter valve 5 bypasses the intercooler10 and directs the charge into the inlet of compressor 1. Compressor 1would compress the charge adiabatically to say, 7:1 compression ratio.ECM 27 controls would bypass intercoolers 11 and 12 and introduce thecharge into manifolds 13 and 14 with the heat-of-compression retained.If the exhaust valves 17, 17′ are closed and the inlet valve 16, 16′ ofcylinder 7 are opened near the end of the compression stroke of piston22 the effective compression ratio can be as low as 2:1, producing a“nominal” compression ratio of 14:1. (If the exhaust valves 17, 17′ areclosed and the inlet valve 16, 16′ are opened earlier in the exhauststroke, the injected charge-air should be of lower pressure and the“effective” compression ratio, that in-cylinder compression producingheat, would be greater. If the intake valves 16, 16′ opened atmid-stroke, after exhaust valves 17, 17′ close, and a nominalcompression ratio of 13:1 were desired with an effective compressionratio of 4:1, then the charge introduced into the cylinder at mid-strokeshould be compressed 4:1.) The uncooled charge is then compressed in thecylinder with an effective compression ratio of 4:1, and in either case,with a pressure of about 530 psi and a temperature above 900° F. Thefuel/air charge is then ignited and expanded against the piston to thefull volume of the power cylinder with an expansion ratio of 19:1.

[0182] At such a time that great power was required, the ECM 27 couldsignal the air bypass valve 4 and 6 to close. Compressor 2 then beginsto compress the air charge to a higher pressure, at the same time ECM 27would open shutter valves 3 and 5 to send the charge-air through theintercoolers 10, 11 and 12. Therefore, as the charge-air is cooled, andcould be to as low as 150-200° F., more air is now pumped into theengine on the back side by the additional compression stage 2, toprevent a substantial pressure drop in the charge-air due to the coolingof the charge before combustion. The air charge in the combustionchamber is now compressed 2:1 (line B(ic), FIG. 13) and is maintainednear the design pressure, in this case about 500-530 psi, althoughcooled, to significantly increase the density of the charge and thetorque and power of the engine. The cooler air charge provides lowerpeak temperature and pressure and coupled with the high turbulencecauses production of less unburned hydrocarbons, NO_(x) and otherpolluting emissions and with smoke and particulates being virtuallyeliminated to a very rich fuel-air mixture. The air-fuel charge is nowignited and expanded to the full volume of the cylinder with anexpansion ratio of 19:1 although the effective compression ratio is only2:1 (see line B (ic) in FIG. 13).

[0183] With either operation scheme the engine can be supercharged to ahigher state than can conventional engines because in most cases theinlet valve is closed at the time of combustion chamber charging and acooler air charge prevents detonation and reduces polluting emissions.Also in most cases residence time of the fuel is less than that requiredfor pre-knock conditions to occur.

[0184] When less power is needed, as during vehicle cruising orlight-load power generation, the engine operation could revert tolight-load operation, e.g., one stage of compression could be cut outand the first cooler 10 bypassed by the air charge being re-circulatedby shutter valve 5 and by bypass valve 6. Shutter valve 3 and air bypassvalve 4 could direct all of the charge from compressor 1 passedintercoolers 11 and 12 with the heat-of-compression retained intomanifolds 13 and 14 and to the cylinder for the less dense, more fuelefficient operation mode.

[0185] Still referring to FIG. 8, there is shown a view of a cylinderhead of the engine of FIG. 8 through FIG. 11 and FIG. 25, showingoptional pressure balanced intake valves with cooling being provided byconduits with intake conduit 29 and outlet conduit 29′, one-way valves(not shown) which allow expansions 28 on the valve stems, as theyreciprocate with intake valves 16 to pump a cooling and lubricating oilor oil-air mixture through the spaces above the valve stem expansions.

[0186] Pressure-balanced intake valves 16, 16′ in FIGS. 8, 11, and 25,and 16-A in FIGS. 9 and 10 provide for rapid intake valve closure andallows large non-restricting intake valves and smaller than normal valvereturn springs. (When the intake valve is opened, pressure equilibriumalmost immediately takes place below the valve head within thecombustion chamber and above the valve head within the intake runner,then the pressure in the intake runner acting on the piston-likearrangement on the valve stem tends to cause the valve stem to followthe down-slope of the cam profile for rapid valve closure. Also, a new“Magnavox” pressure operated, “square wave” intake valve could be usedin the engines of this invention.)

[0187] The operation of the pressure balanced intake valves is in thismanner:

[0188] The pressure balanced intake valves have expansions 28 on thevalve stems, the lower surface of which are exposed to gases in conduit15A. When the valve stem is depressed by a cam 21 and intake valve(s) 16opens in FIG. 8 through FIG. 11, or FIG. 25 any pressure in conduit 15Ais equilibrated with pressure in the combustion chamber and at that timethe only reactive force is by any pressure in conduit 15A which isagainst the underside of valve stems expansions 28, causing a rapidclosure of the valve. One-way valves (not shown) on inlet and outletchannels 29 and 29′ are preferably provided for oil or oil-air mixtureinduction through spaces above expansions 28, and alternatively throughthe valve stem expansions 28. The oil inlet could be at a low point inthe cylinder head where oil would collect to supply the cooling system.Alternatively, oil inlet line 29 could be connected to an oil or oil-airmix supply line. The inlet conduit 29 and the exit conduit 29′ from thecooling system would be fitted with one-way valves and the exit conduit29′ could be higher than the inlet conduit 29 or could be connected toan oil discharge line leading to the engine oil reservoir. The valvestem expansions 28 could also have a channel through them with a one-wayvalve on each side. Since historically exhaust valves have beendifficult to cool, this same system would provide adequate cooling forthe exhaust valves even though there is not great pressure in theexhaust conduit. This system would then be applied to exhaust valves 17from which exhaust ports 18 originate, or to the exhaust valves of anyengine to provide long life for the exhaust valves and the valve seats.

[0189] On large engines the lines from the pumps described here canconverged into larger lines and the oil pumping provided by them couldreplace the conventional oil pump on said engine.

The Engine 100 ⁹ of FIG. 9

[0190] Referring now to FIG. 9, there is shown a six cylinderreciprocating internal combustion engine having one atmospheric airintake, in which all of the cylinders 7 a-7 f (only one (7 f) is shownin a sectional view) and associated pistons 22 a-22 f operate in a2-stroke cycle and all power cylinders are used so as to produce sixpower strokes per revolution of crankshaft 20 for producing power to acommon crankshaft 20 via connecting rods 19 a-19 f, respectively. Aprimary compressor 1, in this figure a double-acting reciprocating type,is shown which, with air conduits as shown, supplies pressurized air toone or more cylinder intake valves 16-A and 16-B (the latter only if aprimary charge to valve 16-B comes from conduit 15). A secondarycompressor 2 of the Lysholm type is shown in series with compressor 1.An air inlet 8 and associated compressors 1 and/or 2 with inlet conduitsand manifolds 13 and 14 supply charge-air, which has been compressed toa higher than atmospheric pressure, to the air intake runner 15-A andintake valve 16-A to cylinder 7. A second conduit 32 directs an aircharge from conduit 110 through optional shut-off valve 33 to intakevalve 16-B to supply lower pressure air to the same cylinder.Alternatively a second conduit 15-B from conduit 15-A can be fitted witha pressure control valve 25 (both in phantom) and can direct the lowerpressure air charge to the intake valve 16-B. Intercoolers 10, 11 and 12and control valves 3, 4 5 and 6 are used to help control the density,weight, temperature and pressure of the charge air. The intake valvesare timed to control the compression ratio of the engine. The combustionchambers are sized to establish the expansion ratio of the engine.

[0191] The engine of FIG. 9, FIG. 11 and FIG. 25 have cam shafts 21fitted with cams and are arranged to rotate at engine crankshaft speedin order to supply one power stroke for each power piston for eachcrankshaft rotation.

[0192] The engine 100 ⁹ shown in FIG. 9 is characterized by a morecomplete expansion process and a lower compression ratio than typicalengines, and is capable of producing a combustion charge varying inweight from lighter-than-normal to heavier-than-normal and capable ofselectively providing a mean effective cylinder pressure higher than canthe conventional arrangement in normal engines with similar or lowermaximum cylinder pressure. Engine control module (ECM) 27 and variablevalves 3, 4, 5 and 6 on conduits as shown provide a system forcontrolling the charge pressure, density, temperature, and mean and peakpressure within the cylinder which allows greater fuel economy,production of greater power and torque at all RPM, with low pollutingemissions for both spark and compression ignited engines. In alternateembodiments, a variable valve timing system with the ECM 27 can alsocontrol the time of opening and closing of the intake valves 16-A or16-B or both, to further provide an improved management of conditions inthe combustion chamber to allow for a flatter torque curve higher powerand with low levels of both fuel consumption and polluting emissions.

Brief Description of Operation of Engine 100 ⁹ Shown in FIG. 9

[0193] The new cycle engine 100 ⁹ of FIG. 9 is a high efficiency enginethat attains both high power and torque, with low fuel consumption andlow polluting emissions.

[0194] The new cycle is an external compression type combustion cycle.In this cycle part of the intake air (all of which is compressed in thepower cylinders in conventional engines) is compressed by at least oneancillary compressor. The temperature rise at the end of compression canbe suppressed by use of air coolers, which cools the compressed air, andby a shorter compression stroke.

[0195] During operation air is supplied to an intake valve 16-B of thepower cylinder 7 which has been increased in pressure by perhapsone-third to one atmosphere or more through an air intake conduit 32leading from ancillary compressor 2, or the air enters by conduit 15-Band a pressure control valve 25. A second air conduit 15A selectivelysupplies charge-air at a higher pressure to a second intake valve 16-Aleading to the same power cylinder 7. (In this design the intake valve16-B admits the low pressure air after exhaust valves 17 open nearbottom dead center in the power stroke, and exhaust blowdown hasoccurred.) Exhaust blowdown occurs after exhaust valve(s) 17 open andnow intake valve 16-B opens and closes quickly to inject low pressurescavenging air. The cylinder 7 is further scavenged by loop scavengingas piston 22 begins its compression stroke. Intake valve 16-B is nowclosed and piston 22 rises in the compression stroke to the point wherecompression should begin at which point exhaust valve 17 closes sealingcylinder 7 and establishing the compression ratio. Compression continuesand at near top dead center, at a point deemed appropriate. fuel beingpresent, the charge is ignited by spark or compression and the powerstroke takes place.

[0196] When more power is desired, a secondary air charge from conduit15-A can be introduced into the power cylinder at the time of, or afterclosure of exhaust valve(s) 17 a during the compression stroke, byintake valve 16-A which introduces a higher pressure air charge, andquickly closes, in order to increase the charge density. Alternatively,the primary air charge may be boosted to a higher pressure by adjustingair bypass valve 6 to send more air through compressor 2, by increasingthe speed of compressor 2 or by changing the setting on the controlvalve 25 on the conduit 15-B which alternatively supplies the lowpressure primary air charge to intake valve 16-B. The temperature,pressure, amount and point of injection of a secondary charge, if added,is adjusted to produce the desired results.

[0197] For light-load operation an intake valve disabler 31 (there areseveral on the market, for example, Eaton Corp. and Cadillac) candisable intake valve 16-A when light-load operation does not require ahigh mean effective cylinder pressure. Alternatively, during the timethe low pressure air to intake valve 16-B is supplied by conduit 15-Bthe air bypass valve (ABV) 6 can be opened to recirculate some of thecharge-air back through the compressor 2 in order to relieve thecompressor of compression work during light-load operation.Additionally, and preferably, air bypass valve 4 can re-circulate partor all of the air pumped by compressor 1 back to the inlet of compressor1 on demand in order to reduce pressure and density of the secondarycharge going through intake valve 16-A.

[0198] One suggested, preferred method of operation of the new-cycleengine 100 ⁹ is thus:

[0199] 1. Intake air at greater than atmospheric pressure that has beencompressed by at least one compressor 2 and has had its temperatureadjusted by bypass systems or charge-air cooler 10, is introduced intothe cylinder 7 through intake valve 16-B, which is opened by a smalllobe on cam 21-B at near bottom dead center, at the end of the powerstroke (perhaps at bottom dead center) after exhaust valve(s) 17, 17′have opened earlier say, at 40° before bottom dead center, for exhaustblowdown. The exhaust valves remain open after bottom dead center forfurther scavenging of the cylinder 7. The intake valve 16-B closes atnear bottom dead center.

[0200] 2. After the power stroke is complete and cylinder 7 is filledwith fresh charge, the exhaust valve(s) 17 is left open for a period oftime after the piston has passed bottom dead center (with intake valve16-B now closed) in order to further scavenge the power cylinder withthe fresh air charge present and further, in order to establish a lowcompression ratio of the engine, the compression ratio being establishedby the displaced cylinder volume remaining at the point of the exhaustvalve 17 closure, being divided by the volume of the combustion chamber.

[0201] 3. With the cylinder 7 now filled with fresh air, the compression(2nd) stroke continues and, at some point the exhaust valve 17 is closedand compression begins for a small compression ratio. This makes itpossible to lessen the temperature rise during the compression stroke.Compression continues, fuel is added if not present, and the charge isfired a the appropriate point near top dead center and the power strokeoccurs.

[0202] 4. (a) Alternatively, when greater power is required, a secondarycompressed, temperature-adjusted air charge is injected into thecylinder 7 by intake valve 16-A opening and quickly closing during thecompression stroke at the point at which the exhaust valve closes, orlater in the stroke, to produce a more dense charge in order to providethe torque and power desired of the engine.

[0203]  (b) When even greater power is required, the secondary aircharge can be increased in density and weight by being passed throughone or more intercoolers 10, 11 and 12 and by increasing compressorspeed or by cutting in another stage of auxiliary compression or bypassing more of the charge air through the operational compressors.

[0204] 5. Near bottom dead center of the piston position, exhaust valves17, 17′ open and the cylinder is efficiently scavenged by blowdown andby the air injected by primary intake valve 16-B.

Detailed Description of the Operation of the Engine 100 ⁹ of FIG. 9

[0205] Near the end of the power (1st) stroke of the piston 22, perhapsat about 40° before bottom dead center position of piston 22, theexhaust valves 17 open for exhaust blowdown, shortly after low pressureair flows through air conduit 32 from conduit 106 and optional shut-offvalve 33 and compressor 2 or alternatively through air conduit 15-Bsupplied by a pressure regulator valve 25 from compressed air line 15-A(as shown in FIG. 9, and FIG. 10), through an intake valve 16-B into thecylinder 7. Intake valve 16-B closes shortly after bottom dead centeror, perhaps at bottom dead center. Exhaust valves 17 remain open duringthe first part of the compression (2nd) stroke of piston 22. Thecylinder 7 is now efficiently scavenged by blowdown and by loopscavenging and at any point during the compression stroke, the cylinder7, now filled with fresh air, the exhaust valves 17, 17′ can close. Butsince a low compression ratio is desired, the exhaust valves 17. 17′ canbe held open until the piston has reached the point that is desired toestablish the compression ratio. At, or after the time exhaust valves 17a and 17 a′ are closed, a secondary charge of high pressure, temperatureadjusted air which has been compressed by a compressor(s) can beinjected by intake valve 16-A into the same cylinder, after which intakevalve 16-A closes. In addition, when very high torque and power isneeded, the density of the secondary charge-air can be greatly increasedby cutting-in compressor 2 or by increasing the speed of compressor 2,if already compressing, as in FIG. 9, directing more air throughcompressors 1 and/or 2 by valves 4 and/or 6, and by routing the chargewholly or in part through intercoolers 10, 11 and 12.

[0206] In this system, regardless of the point the exhaust valve isclosed to establish the compression ratio, the primary fresh air chargetrapped in the cylinder 7 will be lighter than normal and thecompression ratio will be lower than normal, therefore, if needed, ahighly compressed, temperature adjusted air charge can be injected atexhaust valve closure or later in the stroke, to provide a heavier thannormal charge but with the temperature rise being restrained by thecooled charge and the short compression stroke. This produces a greaterthan normal mean effective cylinder pressure when combusted for greattorque and power but still with an expansion ratio greater than thecompression ratio.

[0207] For light-load operation a shut-off valve, or a valve disabler 31(in phantom) on the high pressure intake valve could temporarilyrestrain the intake air, or hold the valve 16-A closed. This would addto the fuel economy of the engine. Alternatively, if compressor 2 is notsupplying air to conduit 32 and intake valve 16-B, during light-loadoperation the shutter valve 5 could be closed and the air bypass valve 6can be opened so that air pumped by compressor 2 would be returned inpart or wholly to the inlet conduit of the compressor 2 with little orno compression taking place there.

[0208] An ancillary automatic intake valve 26, FIG. 10. can be arranged,as shown in FIG. 10, to prevent any back-flow of charge-air into conduit15-A if the cylinder 7 pressure should approximate or exceed thepressure in conduit 15-A during the compression stroke of piston 22before the closure of intake valve 16-A.

[0209] Alternatively, the ancillary automatic valve 26 of FIG. 10 couldbe used to provide a constant or a variable pressure ratio in cylinder7. In this case valve 16A would be kept open to near top dead center andthe closure time of valve 26 would be adjusted by the pressuredifferential in cylinder 7, controlled by valves 3, 4, 5 and 6 bycompressor(s) output and by any throttle valve present. The automaticvalve 26 could be of the spring-retracted disc type and could befabricated of metal or ceramics.

[0210] Fuel can be carbureted, injected in a throttle body 56, shown inFIG. 15 through FIG. 17 and item 56 in FIG. 19 and FIG. 20, or the fuelcan be injected into the inlet stream of air, injected into apre-combustion chamber (similar to that seen in FIG. 21) or, injectedthrough intake valves 16-A, or it may be injected directly into thecombustion chamber at point x during the exhaust-compression stroke, atthe time or after the piston 22 has passed point x in the compressionstroke. The fuel can also be injected later and in the case of dieseloperation can be injected at the usual point for diesel oil injection,perhaps into a pre-combustion chamber or directly into the combustionchamber, perhaps as FIG. 21, or directly onto a glow plug. After thetemperature-and-density-adjusting-air charge has been injected, if used,compression of the charge continues and with fuel present, is ignited atthe opportune time for the expansion stroke. (The compression ratio isestablished by the displaced volume of the cylinder remaining afterpoint x has been reached, being divided by the volume of the combustionchamber. The expansion ratio is determined by dividing the cylinderstotal clearance volume by the volume of the combustion chamber.)

[0211] Now the fuel-air charge is ignited and the power (2nd) stroke ofpiston 22 takes place as the combusted gases expand. Near bottom deadcenter of the power stroke the exhaust valve(s) 17, 17′ open and thecylinder 7 is efficiently scavenged by blowdown and by loop scavengingat the end of the power stroke and largely during the piston 22turnaround time.

[0212] It can be seen that the later the point in the compression strokethat point x is reached (the later the exhaust valve is closed), thelower is the compression ratio of the engine and the less the charge isheated during compression.

[0213] It can also be seen that the later thetemperature-density-adjusting charge is introduced, the less work willbe required of the engine to compress the charge, the later part ofwhich has received some compression already by compressor 1 and/or by anancillary compressor 2. In some cases where the load is light and fueleconomy important the ancillary compressor could be bypassed with thesecondary air charge perhaps eliminated temporarily and the total chargeweight could be less than that of a conventional engine and with theextended expansion ratio produce even better fuel economy.

[0214] During light-load operation of this 2-stroke cycle engine (FIG. 9and FIG. 9-B) such as vehicle cruising or light-load power generation,the secondary air charge can be eliminated by disabling high pressureintake valve 16-A temporarily (several valve disabling systems Eton,Cadillac, etc.) or air can be shut off to intake valve 16-A and theengine still produce greater fuel economy and power with the air chargebeing supplied by compressor 2 or 1 through conduits 15-A, 110, 32 andintake valve 16-B.

The Engine 100 ^(9-B) of FIG. 9-B

[0215]FIG. 9-B is a schematic representation of a six-cylinderreciprocating internal combustion engine 100 ^(9-B) which is for themost part identical to the engine 100 ⁹ of FIG. 9. The characteristicsand operation and structure of the engine 100 ^(9-B) of FIG. 9-B aresubstantially similar to the engine 100 ⁹ of FIG. 9 and, except asnecessary to point out specific points of distinction, suchcharacteristics, operation and structure are not repeated here.Reference should be made to the sections on characteristics, structureand operations (both brief and detailed) previously presented withrespect to the engine 100 ⁹ of FIG. 9.

[0216] The major point of distinction between engine 100 ⁹ and engine100 ^(9-B) is that engine 100 ^(9-B) represents an embodiment of theengine 100 ⁹ wherein the compressors 1, 2 are of alternate types. Thatis, in 100 ^(9-B), the primary compressor 1 is shown as a Lysholm rotarycompressor (as opposed to the reciprocating-type compressor of engine100 ⁹) and the secondary compressor 2 is of the turbo-type (as opposedto the Lysholm-type of 100 ⁹). Although conduit 32 from conduit 110(designated as 106 in FIG. 9) and optional shut-off valve 33 is shownsupplying intake valves 16-B of only two cylinders of the engine, it isunderstood that other intake runners (not shown) distribute air fromconduit 110 to the remainder of the intake valves 16-B of the engine, orthat conduit 32 supplies an “air box” or manifolds which distribute theair to all of the intake valves 16-B.

[0217] Referring now to FIG. 10 there is shown the same engine and thesame operating system as described for the engines of FIG. 9 and FIG.9-B, but has an optional added feature in that the secondary intakevalve 16-A has an ancillary valve 26 which is automatic to preventcharge-air back-flow from cylinder 7. This feature will prevent anyback-flow from occurring during the compression stroke of the engine ofthis invention, should the cylinder pressure approximate or exceed thepressure in conduit 15-A before the intake valve 16-A was fully closed.(This optional automatic valve 26 could be of the spring-retracted disctype, or could be any type of one-way valve.) An automatic valve at thisplace could be used to regulate the pressure ratio in cylinder 7 duringthe compression of the charge. In this case intake valve 16-A could bekept open to near top dead center, valve 26 automatically closing theintake below valve 16-A during compression, ignition and power stroke ofthe charge. Furthermore, the use of automatic valve 26 would allow thepressure ratio of the engine to be adjusted by simply adjusting thepressure in conduit 15-A, with intake valve 16-A being kept open to neartop dead center of piston 22. The ancillary valve 26, if present, wouldalso impart a tangentially oriented swirl turbulence to the combustioncharge as would also, shrouding of intake valve 16-A.

The Engine 100 ¹¹ of FIG. 11

[0218] Referring now to FIG. 11, there is shown a six cylinderreciprocating internal combustion engine 100 ¹¹ with one atmospheric airintake, in which all of the cylinders 7 a-7 f (only one (7 f) of whichis shown in a sectional view) and associated pistons 22 a-22 f operatein a 2-stroke cycle and all power cylinders are used for producing powerto a common crankshaft 20 via connecting rods 19 a-19 f respectively. Aprimary compressor 1, in this figure a double-acting reciprocating type,is shown which, with an air conduits, as shown, supplies pressurized airto one or more cylinder intake valves 16 a and 16 b. A secondarycompressor 2 of the Lysholm type is shown in series with compressor 1.An air inlet 8 and associated inlet conduit and manifolds 13 and 14supply air charge which has been compressed to a higher than atmosphericpressure, to a cylinder intake conduit 15 which supplies charge-air totwo intake valves, which intake valves 16 a and 16 b operateindependently of each other but open into the same cylinder.Intercoolers 10, 11 and 12 and control valves 3, 4, 5 and 6 are used tohelp control the air charge density, weight, temperature and pressure.The intake valves are timed to control the compression ratio of theengine. The combustion chambers are sized to establish the expansionratio of the engine.

[0219] The engine 100 of FIG. 8, FIG. 9, FIG. 10 and FIG. 11 have camshafts 21 fitted with cams and are arranged to rotate at enginecrankshaft speed in order to supply one power stroke for each powerpiston for each crankshaft rotation.

[0220] The engine 100 ¹¹ shown in FIG. 11 is characterized by a moreextensive expansion process, a low compression ratio and capable ofproducing a combustion charge varying in weight from lighter-than-normalto heavier-than-normal and capable of selectively providing a meaneffective cylinder pressure higher than can the conventional arrangementin normal engines, but having similar or lower maximum cylinderpressure. Engine control module (ECM) 27 and variable valves 3, 4, 5 and6 on conduits, as shown, provide a system for controlling the chargepressure, density, temperature, and mean and peak pressure within thecylinder which allows greater fuel economy, production of greater powerand torque at all RPM, with low polluting emissions for both spark andcompression ignited engines. In alternate embodiments, a variable valvetiming system with the ECM 27 can also control the time of opening andclosing of the intake valves 16 a or 16 b or both, to further provide animproved management of conditions in the combustion chamber to allow fora flatter torque curve, and higher power, with low levels of both fuelconsumption and polluting emissions.

Brief Description of Operation of Engine 100 ¹¹ shown in FIG. 11

[0221] The new cycle engine 100 ¹¹ of FIG. 11 is a high efficiencyengine that attains both high power and torque, with low fuelconsumption and low polluting emissions.

[0222] The new cycle is an external compression type combustion cycle.In this cycle part of the intake air (all of which is compressed in thepower cylinders in conventional engines) is compressed by an ancillarycompressor. The temperature rise at the end of compression can besuppressed by use of air coolers, which cools the intake air, and by ashorter compression stroke.

[0223] During operation air is supplied to the power cylinder 7 at apressure Which has been increased by perhaps from one-third to severalatmospheres, or greater through an air intake conduit 15. Valve 16 bopens by pressure on the top of the valve stem from a very small lobe oncam 21-A for a short period of time near bottom dead center position ofpiston 22 in order to scavenge the cylinder and provide freshcharge-air. Exhaust valves 17, 17′ open for exhaust blowdown slightlybefore intake valve 16 b opens to admit scavenging air. The cylinder 7is efficiently scavenged mostly during the turnaround time of piston 22.During the first part of the compression stroke, perhaps as early as10-20° after bottom dead center of piston 22 position, the first intakevalve 16b closes, at a later time the exhaust valve 17, 17′ closes, atwhich point compression of the fresh air charge starts, whichestablishes the compression ratio of the engine. At the point theexhaust valves 17, 17′ closes or any point later, the second intakevalve 16 a and perhaps 16 b, by a second lobe 21-C is, preferably,opened to introduce more of the temperature and density adjusted charge,if needed.

[0224] An intake valve disabler 31 in FIG. 10 (there are several on themarket, for example, Eaton Corp. and Cadillac) can disable intake valve16 a when light-load operation does not require a high mean effectivecylinder pressure. Alternatively, the air bypass valve (ABV) 6 is openedwholly or partially to re-circulate some or all of the charge-air backthrough the compressor 2 in order to relieve the compressor ofcompression work during light-load operation. Additionally, air bypassvalve 4 can re-circulate part or all of the air pumped by compressor 1on demand in order to reduce charge pressure and density.

[0225] One suggested, preferred method of operation of the new cycleengine 100 ¹¹ is thus:

[0226] 1. Intake air at greater than atmospheric pressure that has beencompressed by at least one compressor and has had its temperatureadjusted by bypass systems and charge-air coolers are introduced intothe cylinder 7 through intake valve 16 b which is opened by a very smalllobe 21-D on cam 21-A at or near bottom dead center of piston 22 at theend of the power-stroke, as exhaust valve(s) 17 a, 17 a′ have opened alittle earlier (perhaps 40° before bottom dead center) for exhaustblowdown. The exhaust valve 17 remains open through bottom dead centerfor efficient scavenging of the cylinder 7 by blowdown and loopscavenging. Intake valve 16 b closes as the fresh high-pressure chargevery quickly scavenges the cylinder 7.

[0227] 2. After the power stroke is complete the exhaust valves 17 areleft open for a period of time after the piston has passed bottom deadcenter (with intake valve 16 b now closed) in order to continue toscavenge the power cylinder with the fresh air charge and further, inorder to establish a low compression ratio of the engine, thecompression ratio being established by the displaced cylinder volumeremaining at the point of the exhaust valve 17 closure being divided bythe volume of the combustion chamber. With the cylinder 7 now filledwith fresh air which is near atmospheric pressure, the compression (2nd)stroke continues and, at the point the exhaust valve is closed,compression begins for a small compression ratio. This makes it possibleto lessen the temperature rise during the compression stroke.Compression continues, fuel is added, if not present, and the charge isfired at the appropriate point near top dead center and the power-strokeoccurs.

[0228] 4. (a) Alternatively, at any point deemed appropriate at the timeor after the exhaust valve has closed and compression of the charge hasbegun, a secondary density and temperature-adjusted air charge can beinjected through intake valve 16 a and perhaps by a second lobe 21-C oncam 21-A, through intake valve 16 b. Compression continues with thesecondary air charge injection, fuel is added, if not present, thecharge is ignited and combustion produces a large expansion of thecombusted gases producing great energy. This energy is turned into hightorque and power by the engine.

[0229]  (b) When even greater power is required, the air charge can beincreased in density and weight by being passed through one or moreintercoolers and by increasing compressor speed or by cutting in asecond stage 2 of auxiliary compression, FIG. 11. Alternatively, thetiming of closing exhaust valve 17 and of the opening of intake valve 16a could be altered temporarily to close earlier and to open earlier,respectively, for a larger charge.

[0230] 5. Near bottom dead center of the piston, exhaust valves 17, 17′open and the cylinder is scavenged by blowdown and by the air injectedby primary intake valve 16 b.

Detailed Description of the Operation of the Engine 100 ¹¹ of FIG. 11

[0231] Near the end of the power (1st) stroke of the piston 22, perhapsat about 40° before bottom dead center position of piston 22, theexhaust valves 17 open for exhaust blowdown, shortly after, highpressure air flows through air conduit 15 from manifold 13 and 14, asshown in FIG. 11, through an intake valve 16 b into the cylinder 7, thecylinder 7 is scavenged, intake valve 16 b closes. (Intake valve head 30can be recessed as shown in FIG. 11 in order to form a pipe-like openinginto cylinder 7 so that when the charge-air is highly compressed, and asmuch as 500-530 psi is feasible, the small lobe 21-D on cam 21-A ofintake valve 16 b lets in a small blast of the high pressure air whichis directed downward for loop scavenging, during or just after piston 22turnaround at bottom dead center piston position.) Exhaust valves 17remain open during the first part of the compression (2nd) stroke ofpiston 22. The cylinder 7 is now efficiently scavenged by blowdown andby loop scavenging and at any point during the compression stroke, thecylinder 7, now being filled with fresh air, the exhaust valves 17, 17′can close. But since a low compression ratio is desired, the exhaustvalves 17, 17′ can be held open until the piston has reached the pointthat is desired to establish the compression ratio. At, or after thetime exhaust valve 17 closed, a secondary charge of high pressuretemperature adjusted air which has been compressed by compressor 1and/or 2 can be injected by the second intake valve 16a and, if desired,by another lobe 21-C (in phantom) on the first valve 16 b into the samecylinder. (When high torque and power is needed, the density of thecharge-air can be greatly increased by increasing the speed of theprimary compressor 1 or by cutting in another stage of compression, asin compressor 2, FIG. 11, and routing the charge through aftercoolers10, 11 and 12. Also the speed of compressor 2 can be increased to shovein more charge on the back end.) Compression would continue, for a smallcompression ratio, fuel would be added, if not present, the charge wouldbe ignited and the gases expanded against piston 22 for the powerstroke.

[0232] For light-load operation, a shut-off valve (or a valve disabler31 shown in FIG. 10 on the intake valve 16-A) could temporarily restrainthe intake air, or hold the intake valve 16 a closed. This would add tothe fuel economy of the engine. Alternatively, during light-loadoperation the shutter valve 5 could be closed and the air bypass valve 6opened so that air pumped by compressor 2 would be returned to the inletconduit of the compressor 2 without any compression taking place. In thesame manner valves 3 and 4 could return part of the air being pumpedthrough back to the intake 106 of compressor 1.

[0233] The ancillary automatic intake valve 26, FIG. 10, which can be ofthe spring-returned disc type, can be arranged, as shown in FIG. 10, toprevent any back-flow of charge-air into conduit 15 if the cylinderpressure should equal or exceed the pressure in conduit 15 during thecompression stroke of piston 22 before intake valve 16 a had closedcompletely. (As in other engine designs herein presented the optionalautomatic valve 26 shown in FIG. 10 can be utilized to control thepressure ratio of this engine. If the intake valve 16 a is kept open tonear top dead center, the closure of valve 26 and the pressure ratio ofcylinder 7 would be controlled by control valves 3, 4, 5 and 6 and bycompressor speed and by any throttle valve present.) Automatic valve 26would seal the intake from conduit 15 during the last part of thecompression stroke, ignition of the charge and during the power stroke.

[0234] Fuel can be carbureted, injected in a throttle body 56 in FIG. 15through FIG. 17, and 56 in FIG. 19 and 20, or the fuel can be injectedinto the inlet stream of air, or injected into a pre-combustion chamberor, injected through intake valves 16 a, 16 b, (the latter during itssecond opening by lobe 21-C on cam 21-A), or it may be injected directlyinto the combustion chamber at or past point x in theexhaust-compression stroke. The fuel can also be injected later and inthe case of diesel operation can be injected at the usual point fordiesel oil injection, perhaps into a pre-combustion chamber or directlyinto the combustion chamber or directly onto a glow plug. After thetemperature-and-density-adjusting-air charge has been injected, if used,compression of the charge continues and with fuel present, is ignited atthe opportune time for the expansion stroke. (The compression ratio isestablished by the displaced volume of the cylinder remaining afterpoint x (at exhaust valve closure) has been reached, being divided bythe volume of the combustion chamber. The expansion ratio is determinedby dividing the cylinders total clearance volume by the volume of thecombustion chamber.) Now the fuel-air charge has been ignited and thepower stroke of piston 22 takes place as the combusted gases expand.Near bottom dead center of the power stroke, the exhaust valve(s) 17opens and the cylinder 7 is efficiently scavenged, first by blowdown,then by loop scavenging by air from intake valve 16 b at the end of thepower stroke or shortly after.

[0235] It can be seen that the later the point in the compression strokethat point x (the later the exhaust valve is closed) is reached, thelower is the compression ratio of the engine and the less the charge isheated during compression.

[0236] It can also be seen that the later thetemperature-density-adjusting charge is introduced, the less work willbe required of the engine to compress the charge, the later part ofwhich has received some compression already by compressor 1 and/or by anancillary compressor 2. In some cases where the load is light and fueleconomy important the ancillary compressor could be bypassed with thesecondary air charge perhaps eliminated temporarily and the total chargeweight could be less than that of a conventional engine.

[0237] Referring now to FIG. 12 there is shown a pressure-volume diagramfor a high-speed Diesel engine compared to the engines of thisinvention, showing three stages of intercooled compression and a fourthstage of uncooled compression indicating a compression ratio ofapproximately 2:1, which arrangement is suggested for optimum power,with efficiency for the engine of this invention. (The charts of FIG. 13and FIG. 14 show some of the improvements of the engine of thisinvention over current heavy-duty 2-stroke and 4-stroke engines.)

[0238] There are several features that improve the thermal efficiency ofthe engine of this invention. Greater power to weight ratios willprovide a smaller engine with less frictional losses. The extendedexpansion ratio results in higher thermodynamic cycle efficiency, whichis shown in theoretical considerations. There are also definiteefficiency gains in a “staged” compression process even with externalcompressors with associated piping, intercoolers and aftercoolers, etc.There is a very significant energy savings when air is compressed inintercooled stages. Less energy is used in compressing a charge to 500psi in 2, 3 or 4 intercooled stages than is used to compress the hotcharge to the same 500 psi in a conventional engine. A normal engineuses approximately 20% of its own energy produced to compress its own orcharge. Calculations show a significant energy savings in an engine ifthe air is compressed in afercooled stages. Compressing a charge in onlytwo stages to 531 psi (a 13:1 compression ratio) reduces the energy usedby 15.8% over compressing to the same 531 psi level in a single stage asdoes the Otto and the Diesel Cycle engines. Three stages of intercooledcompression raises the savings to 18%. This is the ideal. Degradationfrom the ideal should not exceed 25% which leaves a 13.5% energysavings. This 13.5% energy savings times the 20% of a normal engine'spower used for compressing its own charge, is a 2.7% efficiencyimprovement by the compression process alone. This is one of theadvantages of this eneine which adds to the other thermal efficiencyimprovements. The low compression ratio, along with the large expansionratio provides improvements in efficiency, torque, power and durabilitywhile lowering polluting emissions.

[0239] Note 1—In FIG. 12 the travel distance of the line for engine B onthe horizontal coordinate indicates the theoretical volume at thegreater density. The density is kept at that level at the actualcombustion chamber volume (as shown by dashed line V) regardless of thedensity, by pumping in more charge at the back-side.

[0240] Referring now to FIG. 13, there is shown a chart which comparesvarious operating parameters of the engine of this invention (B) withthe operation parameters of a popular heavy-duty, 2-stroke diesel cycleengine (A).

[0241] The parameters shown for engine A are the normal operatingparameters for that engine, e.g., compression ratio, combustiontemperatures, charge density, etc. The parameters chosen to illustratefor engine (B) are given at two different lower “nominal” compressionratios with corresponding “effective” compression ratios, intercooledand uncooled, for two different levels of poster output. The columnsshowing charge densities and expansion ratios indicate the improvementsin steady state power density improvements for engine B even at asubstantially lower nominal compression ratio and an effectivecompression ratio as low as 2:1 as shown in FIG. 10. The columns showinglow temperatures at the end of combustion, and the column showingextended expansion ratios, indicate much lower polluting emissions.Indicated power improvements of engine (B) over engine (A) even at thelower nominal compression ratio are no less than 50%.

[0242] Referring now to FIG. 14 there is shown a chart which comparesthe various operating parameters of the engine of this invention (B)with the operating parameters of a popular heavy-duty 4-stroke dieselengine (A).

[0243] When comparisons similar to those of FIG. 13 are made, steadystate power and density improvements are much higher since engine (B)fires the denser charge twice as often as engine A for an indicatedsteady-state power density improvement of 180% over engine (A).

[0244] Referring now to FIG. 15, there is shown a schematic drawing ofan engine representing the engines of FIGS. 5-7, and FIGS. 9-1 0 with aseparate air cooler 10 for ancillary compressor 2, with the primarycompressor 1 supplying two manifolds 13 and 14 and having separate aircoolers 11 and 12 and charge-air conduits 114 and 115, and having eachmanifold having three cylinder air intake runners 15 a-15 c, 15 d-15 f,respectively. The engine of FIG. 15 operates the same as the engines ofFIGS. 5-7 and FIGS. 9-10 and here shows suggested valving positions forshutter valve and air bypass valves for supplying the manifolds 13 and14 with an air charge optimum for light-load operation of the engine ofFIGS. 5-7 and FIGS. 9-10. For light-load operation, the shutter valve 5can be closed and the air bypass valve 6 of compressor 2 (if compressor2 is not supplying primary air charge directly to conduit 32 and intakevalve 15-B) can be opened filly or partially so that part or all of theintake air of compressor 2 can be returned to the intake of compressor 2with little or no compression occurring there. Also, the shutter valve 3of compressor 1 can be closed, passing the air charge away from thecoolers 11 and 12, the air bypass valve 4 would be closed to preventre-circulation of the now compressed and heated air back throughcompressor 1 and whose shutter valve 3 and air bypass valves are bothdirecting the air charge uncooled into manifold 13 and 14 for a lowdensity heated charge for light-load operation. Preferably compressor 2would be kept operative in order to supply the primary air chargethrough conduits 110, 32 and intake valve 16-B for a more economicalscavenging-charging system.

[0245] Referring now to FIG. 16, there is shown suggested valvepositions for supplying manifolds 13 and 14 with an air charge optimumfor medium-load operation for engines of FIG. 16 or for the engines ofFIGS. 5-7 and FIGS. 9-10. For medium-load operation the shutter valve 5of compressor 2 is closed and the air bypass valve 6 would be opened topass the air charge uncooled and without compression to the intake ofcompressor 1 where closed shutter valve 3 and closed air bypass valve 4directs the air charge now compressed by compressor 1 past theintercoolers to manifolds 13 and 14 with the air compressed and heatedby compressor 1, for medium-load operation.

[0246] Referring now to FIG. 17, there is shown a suggested scenario forproviding the engine of FIG. 17 or for the engines of FIGS. 5-7 andFIGS. 9-10 with a high density air charge for heavy duty, high poweroutput operation. FIG. 17 shows both shutter valves 3 and 5 open andboth air bypass valves 4 and 6 closed completely so that the primarystage of compression is operative and a second stage of compression hasbeen made operative for maximum compression of the charge and the entireair charge is being passed through the intercoolers 10, 11 and 12 toproduce a cooled, very high density air charge to manifolds 13 and 14and to the engines power cylinders for heavy-load operation. Thisproduces a very high mean effective cylinder pressure for high torqueand power with maximum cylinder pressure being the same as, or lowerthan that of normal engines.

[0247] Referring now to FIG. 18, there is shown a schematic drawing ofan alternative type of auxiliary compressor 2′ for the engines of FIGS.5-7 and FIGS. 9-10 and for any other engine of this invention and asystem of providing a system for cutting out the auxiliary compressorwhen high charge pressure and density is not needed. For relievingcompressor 2′ of work, (if the air compressed by compressor 2 does notgo directly to conduit 32 and valve 16-B to supply the primary aircharge) shutter valve 5 is closed and air bypass valve 6 is opened sothat air pumped through compressor 2′ can re-circulate throughcompressor 2, thus relieving the compressor of compression work.

[0248] Referring now to FIG. 19, there is shown a schematic drawing ofthe engines of FIGS. 5-7 and FIGS. 9-10, illustrating means ofcontrolling charge-air density, temperature and pressure by varyingdirections of air flow through various electronic or vacuum operatedvalves and their conduits.

[0249]FIG. 19 also shows the various charge-air paths possible by usinghollow arrows to indicate heated air paths and solid arrows to indicatethe more dense intercooled air paths thereby indicating how charge-airtemperatures can be thermastatically or electronically controlled bydividing the air charge into two different paths. Alternatively, all ofthe air charge can be directed past the air coolers or all can bedirected through the air coolers, as shown in FIG. 19. Also, FIG. 19shows how the pressure output of compressor 1 and compressor 2 can bevaried by partially or fully opening air bypass valves 4 and 6 or bycompletely closing one or both of these control valves. An enginecontrol module (ECM) 27 is suggested for controlling the variousoperating parameters of the engines of this invention.

[0250] Referring now to FIG. 20. there is shown is a schematic drawingdepicting an alternate arrangement in which an electric motor 34preferably drives the compressor(s) of any of the engines of the presentinvention.

Charge-Air Cooler Bypass (ACB) “Shutter Valve” Control

[0251] In this section are described aspects of preferred controlcomponents which find application in connection with any of the engines(4-stroke and 2-stroke) of the present invention.

[0252] Outline: Valves 3 and 5 are charge-air-cooler bypass solenoid(ACB) valves. In charge-air cooler bypass control, the intake air isswitched between two routes by valves 3 and 5, independently of eachother: either (a) valve 5 directs the flow from compressor 2 directly tothe intake conduit of compressor 1 or (b) through the charge-air cooler10 before flowing to the intake conduit of compressor 1. Valve 3 directsthe flow from compressor 1 either (a) to the conduit 111/121/122 leadingdirectly to the intake manifolds 13 and 14 or (b) it passes the aircharge through charge-air coolers 11 and 12 before it flows to manifolds13 and 14.

[0253] An engine control module (ECM) 27 can control the air coolerbypass valves 3 and 5. The bypass valves may be a shutter type valve topass all or none of the air charge in either direction or valves 3 and 5may be of a helical solenoid or other type of valve which can pass partof the air charge through bypass conduits 121 and 122 and part throughair coolers 10, 11 and 12 for fine control of the temperature anddensity of the air charge. The ECM could receive signals from sensorssuch as an engine coolant sensor, a crankshaft position sensor, throttleposition sensor, camshaft position sensor, a manifold absolute pressuresensor and a heated oxygen sensor.

Air Bypass Valve (ABV) Control

[0254] Outline: To provide optimum air charging pressure for differingengine operations conditions, the ECM 27 can send signals to control airbypass valves 4 and 6. These valves could be on-off solenoid valves,possibly vacuum operated, or they could be helical solenoids or othertype of valve which could open part way or all way in order tore-circulate part or all of the air charge back through the inlets 110and 8 of compressors 1 and 2 in order to reduce or eliminate entirelythe pumping pressure of either compressor 1 or compressor 2, or both.Similar arrangements of air pressure control could be used foradditional stages of air compression if additional stages are used.

[0255] The operation could be thus: The ABV valves 4 and 6 can becontrolled by signals from the ECM 27 to control the opening angle ofvalves 4 and 6 to provide the optimum air charging pressures for variousengine loads and duty cycles. When ABV 6 is opened partially some of theair pumped through compressor 2 is passed back into the intake 8 ofcompressor 2 to reduce compression pressure. When ABV 6 is opened fullyall of the charge of compressor 2 is passed back through compressor 2,thus compressor 2 only pumps the charge through with no pressureincrease. The system can work the same for valve 4 which could bypasssome of the air charge pumped by compressor 1 back into the intakeconduit 110 of compressor 1 in order to reduce air charge density.

[0256] With this arrangement, combined with the arrangement of ECM 27control of charge-air cooler bypass system for variable valves 3 and 5,the temperature, density, pressure and turbulence of the charge-air canbe managed to produce the desired power and torque levels and emissionscharacteristics in the power cylinder of the engine.

[0257] Engine conditions that could be monitored by ECM 27 in order toeffect proper engine conditions in regard to control of ABV valves 4 and6 could include a throttle position sensor (or fuel injection activitysensor), intake air temperature sensor at various points, manifoldabsolute pressure sensor, camshaft position sensor, crankshaft positionsensor, exhaust temperature sensor, a heated oxygen sensor and/or othersensory inputs known to be used in internal combustion engines.

[0258] The ECM 27 can control both the shutter valves 3 and 5 and theair bypass valves 4 and 6 in order to maintain the optimum air chargingdensity pressure and temperature at all engine operating duty cycles.

Alternate Combustion Systems

[0259] Referring now to FIG. 21, there is shown a schematic transverseview of a pre-combustion chamber 38′, a combustion chamber 38, a pistoncrown 22 and associated fuel inlet 36, a sparking plug 37, an air orair/fuel mixture inlet 8′ duct, intake valve 16, an exhaust duct 18′ anexhaust valve 17 suggested for liquid or gaseous fuel operation for theengines of this invention or for any other internal combustion engine.

[0260] There are many choices of systems for compression or sparkignition combustion for the engine of this invention, as shown in FIG. 1through FIG. 33. Every fuel from avgas to heavy diesel fuels, includingthe alcohols and gaseous fuels can be spark ignited (SI) in this engine.One good SI system would be similar to the system shown in FIG. 21 forcompressed natural gas, propane, hydrogen, gasoline, alcohols or dieselfuel. In this system, an extremely fuel rich mixture constituting theentire fuel charge is, preferably, injected into the pre-combustionchamber 8′. The fuel could be injected through fuel duct 36 with orwithout air blast injection, the air charge, some of which can accompanythe fuel charge would be compressed into the pre-combustion chamber 38′by piston 22 during the compression stroke. Additional air with orwithout additional fuel, could be introduced into the cylinder propereither on the intake stroke or on the compression stroke through intakeconduit 8′. In either case the second combustion stage in the cylinderproper would be with a lean mixture.

[0261] The two-stage combustion system shown in FIG. 21 will operate inthis manner:

[0262] 1. Pre-Combustion (first stage)

[0263] Pre-combustion occurs in the pre-combustion chamber 38′ when fuelin an amount much in excess of the amount of oxygen present is injectedand ignited (injector not shown). This oxygen deficiency along with thecooler, turbulent charge and lower peak temperatures and pressuresgreatly reduces the formation of oxides of nitrogen. The combination ofthe hot pre-combustion chamber wall and intense turbulence promotes morecomplete combustion.

[0264] 2. Post-Combustion (second stage)

[0265] Post-combustion takes place at lower pressure and relatively lowtemperature conditions in the space above the piston in the cylinder asthe gases expand from the first stage pre-combustion chamber into thecylinder proper. If there is additional fuel in the cylinder proper, theleaner mixture is ignited by this plasma-like blast from thepre-combustion chamber. The low temperature and the admixture of burnedgases prevent any further formation of oxides of nitrogen. Excess air, astrong swirling action, and the extended expansion process assure morecomplete combustion of carbon monoxide, hydrocarbons, and carbon.

[0266] The results of the engine of this invention using thepre-combustion chamber 38′ of FIG. 21 are: higher thermal efficienciesdue to the greater expansion, along with a cooler exhaust and a lowerlevel of polluting emissions including oxides of nitrogen, and inaddition for diesel fuels, lower aromatics and particulates.

[0267] Referring now to FIG. 22 there is shown a schematic transversesectional view of an optional cylinder of the engine of this inventionwhich will convert the 2-stroke engine of FIG. 8 through 33 to aone-stroke cycle engine and will convert the 4-stroke engines of FIG. 1through FIG. 7 and FIG. 33 to operate in a 2-stroke cycle.

[0268] By building any 2-stroke engine with all power cylinders doubleacting, the power to weight ratio can be doubled over the basic engine.One end of the cylinder fires and the other end is scavenged on eachstroke for a nominal one stroke cycle engine in the engines of FIG. 8through FIG. 33. Use of double-acting power cylinders in the 4-strokeengine of FIG. 1 through FIG. 7 and FIG. 3 converts the engine to a2-stroke engine because one end of the cylinder is scavenged and one endis fired during each crankshaft rotation.

[0269] In the design of FIG. 22 needed variation of beam 39 length isaccomplished by the beam end forming a scotch yoke 40 and fitting overthe wrist pin 41 of the piston.

[0270] The double ended piston 22″ can be linked to the end of avertical beam 39 that pivots at the lower end 42. A connecting rod 19′is joined between the midpoint of the beam and the crankshaft 20′.

[0271] Since the crankshaft 20′ itself does no more than transmittorque, its main bearings will be very lightly loaded. As a resultlittle noise will reach the supporting casing. Because of the leveraction, the crank (not shown) has half the throw of the piston strokeand can be a stubby, cam-like unit with large, closely spaced pinshaving substantial overlap for strength.

[0272] The compression ratio can be changed by slightly lengthening orshortening the effective length of the beam 39. This can be done by thelower pivot plate 42 being attached to a block 43 mounted slidably in afixed block 44 and in which block 43 can be moved slidably by a servomotor 45. The gear 45 a rotated by servo motor 45 is much longer thanthe gear 44a on the screw 43 b which is rotatably attached to block 43and rotates against threads in block 44, causing gear 44 a to slide backand forth on gear 45 a as block 43 reciprocates in block 44. Thus as adiesel, it could be started at 20:1 ratio and then shifted to a 13:1ratio for less friction and stress on parts. This could also beimportant to allow use of alternate fuels.

[0273] Referring now to FIG. 23: These same advantages hold true for thealternate design (FIG. 23) in which the pivot 47′ is between theconnecting rod 19 and the piston 22″

[0274] The needed variation of the length of the beam 39 (shown inphantom) connecting the piston 22″ to the connecting rod 19 can beaccomplished by forming a scotch yoke 40 on the beam end fitting overthe wrist-pin 41 of the piston 22″, or by placing a double pivoting link42′ between the pivot 47′ on the fulcrum of beam 39′ with the pivot 42″being attached to a non-movable part 46 of the engine and the terminalend of beam 39′ being connected to connecting rod 19 by a pin 47.

[0275] Alternately and preferably, for heavy duty engines (marinepropulsion, power production, etc.) the power take off of piston 22″could be with a conventional piston rod 39′ being arranged betweenpiston 22″ and a crosshead 20′ with a connecting rod 19′ between thecrosshead 20′ and the crankshaft (not shown).

[0276] Double-acting power cylinders when used in the engine of thisinvention will be especially of importance where great power is desiredand cooling water is readily available, e.g., for marine use or forpower generation.

[0277] These double-ended, double-acting cylinders can be used in all ofthe designs of this invention.

[0278] Referring now to FIG. 24: There is shown a schematic transversesectional view of a crankshaft, two connecting rods 19′ and 19″ and abeam 39 showing a means of providing extra burn time of a conventional2-stroke or 4-stroke engine.

[0279] This layout for any engine provides for double the piston 22′turnaround time of a normal engine during the critical burn period. Thisis because piston 22′ top dead center (TDC) occurs at bottom dead center(BDC) of the crank 48. At this point, crankpin motion around piston 22′top dead center is subtracted from the straightening movement of theconnecting rod 19′, instead of being added to it as in conventionalengines. Reversing the usual action slows piston travel around thispoint, resulting in more complete combustion and further reducingemissions.

[0280] The extra burn time provided by the design of FIG. 24 can beimportant in the engines of this invention and to any Otto or Dieselcycle engine.

[0281] Operation of the engine constructed and arranged with theadditional burning time would be the same as the other engines of thisinvention providing high charge density, low compression-ratios with amean effective pressure higher than conventional engines but with morecombustion time than other engines while producing even less pollutingemissions.

[0282] Since the crankshaft 48 in FIG. 24 itself does no more thantransmit torque, its main bearings will be very lightly loaded. As aresult little noise will reach the supporting casing. Because of thelever action, the crank can have as little as half the throw of thepiston stroke (depending on the point of the fulcrum), and can be astubby, cam-like unit with large, closely spaced pins having substantialoverlap for strength.

[0283] This layout also provides for nearly twice the combustion time ofa conventional engine during the critical burn period. This is becausepiston top dead center occurs at bottom dead center (BDC) of the crank.

The Engine 100 ²⁵ of FIG. 25

[0284] Referring now to FIG. 25 of the drawings, there is shown a sixcylinder reciprocating internal combustion engine in which all of thecylinders 7 a-7 f (only one (7 f) of which is shown in a sectional view)and associated pistons 22 a-22 f are adapted to operate in a 2-strokecycle and all cylinders are used for producing power to a commoncrankshaft 20 via connecting rods 19 a-19 f, respectively. A compressor2 supplies air to scavenging ports 52 by way of optional shut-off valve33-M and conduit 32 and to cylinder charge inlet valve(s) 16 and 16′ byway of conduits 15. The engine of FIG. 25 is adapted to operate in a2-stroke cycle so as to produce six power strokes per revolution of thecrankshaft 20. To this end, compressor 1 takes in an air charge whichmay have been previously subjected to compressing to a higher pressure,via an admission control valves 5 and 6 through an intake conduit 110,leading from compressor 2 by way of intercooler 10 or bypass conduit 104and shutter valve 5 During operation of the engine of FIG. 25,compressor 2 receives atmospheric air through inlet opening 8,pre-compresses the air charge into conduit 101 leading to controlshutter valve 5 which in response to signals from the ECM 27, to shuttervalve 5 and air bypass valve 6, will direct the compressed chargethrough intercooler 10 or through cooler bypass conduits 104 tocompressor 1. The air charge is compressed within compressor 1 by itsassociated piston 131, and the compressed air charge is forced throughan outlet into a high pressure transfer conduit 109 which leads tocontrol shutter valve 3 which, if open, directs the air throughintercooler 11 and 12 to manifolds 13 and 14 or, if closed, through aconduit and air bypass valve 4 which can direct part of the air chargeback through inlet conduit 104 of the compressor 1, or valve 4 if fullyclosed, directs all of the charge from compressor 1, in response tosignals from the engine control module (ECM) 27, through theintercoolers 11 and 12 or through the bypass conduit 111/121/122 intomanifolds 13 and 14. Manifolds 13 and 14 are constructed and arranged todistribute the compressed air charge by means of branch conduits 15 a-15f to inlet valves 16 and 16′ of the cylinder 7 a, and to the remainingfive power cylinders 7 b-7 f. In an alternate embodiment, instead ofproviding scavenging air through conduit 32′, scavending air is providedthrough shut-off valve 49 and conduit 50 and pressure reducing valve 25to air box 51, through conduits 125 a-125 f to scavenging ports 52 a-52f.

[0285] The engine 100 ²⁵ shown in FIG. 25 has a camshaft which isarranged to be driven at the same speed as the crankshaft in order tosupply one working stroke per revolution for the power pistons. Thecompressor can be reciprocating, comprised of one or more stages ofcompression with one or more double-acting cylinders, one is shown, 1 inFIG. 25. The compressor can be driven by associated connecting rods 19 gto crankshaft 20 which can have throws of different lengths fordifferent length piston strokes for the air compressor(s) than those ofthe power pistons. In addition, compressor 1 can be driven by a secondcrankshaft (not shown) which is driven by a gear meshing with a step-upgear mounted on the common crankshaft. The ancillary rotary compressor,a Lysholm type is shown 2, can be driven by a V-pulley being rotated bya ribbed V-belt and has a step-up gear arranged between the V-pulley andthe compressor drive shaft. The rotary compressor 2 could also have avariable speed, or two speed drive, as in some aircraft engines.

[0286] The operation of engine 100 ²⁵ shown in FIG. 25 is thus:Charge-air is inducted into the inlet opening 8 of compressor 2. Fromthere it is pumped through the compressor 2 where it is directed byshutter valve 5 through the intercooler 10 or through a conduit to airbypass valve 6 where it is directed to the inlet of compressor 1. Thecharge is then pumped by compressor 1 through the outlet valve toshutter valve 3 which directs the air charge either through intercoolers11 and 12, to manifolds 13 and 14 or into a conduit leading to airbypass valve 4 which can direct a part of the charge back through theinlet of compressor 1 or valve 4 directs the charge wholly or partiallyto the shutter valve 3 which directs the charge wholly or partiallythrough intercoolers 13 and 14, or directly to manifolds 13 and 14 whichdistributes the temperature-adjusted charge-air to cylinder 7 inletvalves 16 and 16′ to each power cylinder of the engine. An off-and-oncontrol valve (not shown) and conduit 32′ directs air to air box 51 andto scavenging ports 52 a-52 f in the bottom of cylinders 7 a-7 f. In thealternates embodiment (shown in phantom in FIG. 25), the scavenging airis directed through pressure reduction valve 25, arranged on conduit 50to provide and adjust scavenging air pressure from compression 1.Another option to reducing the manifold air pressure for scavenging thecylinders 7 a-7 f is to use the manifold air through conduit 50, air box51 and intake ports 52 a-52 f without reducing the pressure frommanifolds 13 and 14. The air would be used at full pressure forscavenging by the scavenging ports 52 a-52 f in FIG. 25 and throughinlet port 52″ and exhaust port 52′ in FIG. 30, which ports 52 a-52 f,52′ and 52″ would be constructed much smaller than normally done. Inthis instance, although the scavenging ports were smaller-than-normal,the higher-than-normal pressure scavenging air would be very efficient.Several means of scavenginq the cylinders are suggested herein. FIG. 26illustrates more clearly (although in phantom) the preferred system ofsupplying low pressure scavenginc air. Conduit 32′ and valve 33 (shownin phantom in FIG. 26) channels air from conduit 110 from compressor 2to conduit 50 which supplies scavenging air to air box 51.

[0287] The engine control module (ECM) 27 (see, for example, FIG. 26)controls valves 3, 4, 5, and 6 in order to adjust the pressure,temperature and density of the charge going to the combustion chambersand valve 25, and can selectively direct a portion, a portion at areduced pressure of the air charge to scavenging ports 52 and cancontrol valve 53 and valves 49′ to open or close to select the mode ofscavenging desired. The ECM can also control a variable-valve-happeningcontrol system to adjust the valve opening time and duration of openingtime of inlet valves 16 and exhaust valves 17 in relationship to thedegree or angle of rotation of crankshaft 20, in order to adjust thecompression ratio of the engine for optimum performance in regard topower, torque, fuel economy, fuel characteristics and to scavenging modedesired.

[0288] The preferred operation of the power cylinders shown in FIG. 25is in this manner:

[0289] After blowdown and scavenging of the cylinder 7 has taken placethe cylinder is now filled with fresh air, and piston 22 has closedexhaust ports 52 and the piston 22 is in its scavenging-charging strokeand is rising with the exhaust valve 17 still open, at any point,perhaps as early as 120 to 90 degrees before top dead center, theexhaust valve 17 is closed to establish the compression ratio and begincompression, intake valve 16, 16′ are opened at that time or later inorder to produce the desired charge density and weight desired, thecompressed air charge or fuel air mixture is injected through intakevalve 16, 16′, intake valve 16, 16′ is then closed. Compression of thecharge which started at point X, the point where exhaust valve 17 wasclosed continues with the compression ratio being established by thecylinder clearance volume remaining at point x. divided by thecombustion chamber volume. Fuel can be injected into the secondarycompressed air stream being injected into the combustion chamber orinjected into a pre-combustion chamber (one is shown in FIG. 21) or maybe injected directly into the combustion chamber. After the closure ofintake valve 16, 16′, the fuel or more fuel can be injected into themidst of the charge swirl for a stratified charge combustion process, oras in compression ignited engines fuel can be injected directly into thecombustion chamber, perhaps directly onto a glow plug, if suggestedpre-combustion chamber is used or not, and can be injected continuouslyduring part of the expansion stroke for a mostly constant pressurecombustion process.

[0290] The fuel-air mixture is ignited by spark plug, by compressionignition, or by glow plug at the point deemed most efficient, preferablybefore top dead center of the compression of piston 22. The expansionstroke of piston 22 takes place as the expanding gases force the pistontoward bottom dead center. Near the end of the power stroke, perhapsabout 40° before bottom dead center, scavenging ports 52 are uncovered,near the same time exhaust valve(s) 17 in the engine head are opened anda rapid blowdown and scavenging takes place in any of four ways as shownin FIG. 27, FIG. 28, FIG. 29 and FIG. 30. In any case the exhaust valves17, 17′ remain open past bottom dead center and for a significant partof the scavenging-charge-adjusting stroke in order to establish theengines compression ratio.

[0291] Referring now to FIG. 26, there is shown a schematic drawingshowing an engine similar in structure and operation to the engine 100²⁵ of FIG. 25, having two compressors, but differing in that compressor1 is depicted as a Lysholm rotary compressor, and compressor 2 isdepicted as a turbo compressor, and having one air cooler for thesecondary compressor two air coolers for the primary compressor, dualmanifolds, with shutter controls, air by-pass controls and conduits fordifferent air paths. Also shown is an engine control module (ECM) 27which can control charge and scavenging air pressures, density andtemperatures in order to effect the desired output and emissionscharacteristics of the engine. Alternate sources of scavenging air areshown, the preferred one being from conduit 110 by way of conduit 32′.Air paths are shown by arrows, hollow arrows for uncooled compressed airand solid arrows for cooled denser air. Also shown are air bypass valves(in this case both closed) which, with the shutter valves (one of whichis closed and one of which is partly open, the latter to allow coolingof part of the charge), can control the charge temperature, weight anddensity as required for best engine performance.

[0292] Referring now to FIG. 27, there is shown one system of efficientscavenging of the exhausted products of the engine of FIG. 25;

Scavenging System A (FIG. 27)

[0293] Blowdown of exhaust occurs at from about 40° before bottom deadcenter to perhaps 40-50° after bottom dead center, with exhaust valves17 opening at approximately the same time the ports 52 are opened andremaining open after bottom ports are closed by piston 22, and closinglater causing a low compression ratio.

[0294] Scavenging air can be supplied from a manifold with perhaps apressure-reducing valve 25 on conduit 50 or, preferably scavenging aircan be supplied from conduit 32′ from ancillary compressor 2, (shown inphantom). In this case, bottom ports 52 open shortly before exhaustvalves 17 open. Blowdown occurs through bottom ports 52 out throughbottom exhaust conduit and valve 53 to main exhaust pipe 18, at sametime or shortly after, exhaust valves 17 open and blowdown of theexhaust occurs both at the top of the cylinder through exhaust valves 53and 17, and through exhaust manifold 18′ and pipe 18 to the atmosphere.The exhaust valve 17 then stays open through a significant part of the2nd or exhaust-charge stroke for additional scavenging, this part bypositive displacement. During this scavenging-charging stroke theexhaust valve 17 may be closed at any point after the first 20 percentof piston 22 travel. Now at any point with cylinder 7 being now filledwith fresh air, exhaust valve 17 can close and intake valve 16′ open toadmit pressurized air which has its temperature adjusted to what isdeemed proper. The later in the exhaust-charging stroke the exhaustvalve 17 is closed, the lower is the compression ratio of the engineestablished. If closed early enough the effective compression ratio canbe as much as 13 or 16 to 1, if closed later the effective compressionratio can be as low as 2:1. At any point after exhaust valve 17 hasclosed, and the compression ratio has been established, and beforepiston 22 has reached top dead center, the air charge, with temperaturedensity and pressure adjusted may be introduced by opening and thenclosing intake valve 16. All of the operating parameters suggested woulddepend on the duty cycle of the engines, e.g., power requirements,efficiency, emissions considerations and the fuel used.

[0295] An engine control module (ECM) 27 is shown with connections tothe critical control valves of the engine which can be adjustedaccording the conditions signaled to the ECM 27 from various sensors inthe engine.

[0296] Referring now to FIG. 28, there is shown a second system ofefficiently scavenging the engine of FIG. 25;

Scavenging System B (FIG. 28)

[0297] Exhaust blowdown occurs through exhaust valves 17 only, withscavenging air being supplied by compressor 2 by way of conduit 32′, oralternatively from manifolds 13 and 14 through conduits 50 past controlvalve 49 and optional pressure control 25 into air box 51 and throughscavenging ports 52 in the bottom of the cylinders 7, up through thecylinder 7, out exhaust valves 17 and through exhaust pipe 18, withvalve 53 being closed. In this system as piston 22 approaches bottomdead center in the power expansion stroke, ports 52 would be uncoveredby piston 22 and as blowdown occurs pressurized air would be injectedthrough all bottom ports 52 and would sweep combusted products throughexhaust valves 17 which open perhaps before ports 52 for the exhaustblowdown. The bottom ports can be constructed to open at perhaps 40°before bottom dead center and could close at the same point after pistonbegins its second stroke. The exhaust valves 17 could remain open afterbottom ports 52 are closed to aid in scavenging by positive displacementby piston 22 and to establish the desired compression ratio which isestablished by the point at which exhaust valves 17 close.

[0298] During this scavenging-charging stroke of piston 22 the cylinder7 being now filled with fresh air, the exhaust valve 17 may be closed atany point after the first 20 percent or so of piston 22 travel. Now atany point exhaust valve 17 can close and intake valve 16 can open toadmit highly pressurized air which has its temperature and densityadjusted to what is deemed proper. The later in the exhaust-chargingstroke the exhaust valve 17 is closed, the lower is the effectivecompression ratio of the engine established. If closed early enough theeffective compression ratio can be as much as 13 or 19 to 1, if closedlater the effective compression ratio can be as low as 2:1. All of theoperating parameters suggested would depend on the duty cycle of theengines, e.g., power requirements, efficiency and emissionsconsiderations and the fuel used.

[0299] An engine control module 27 is suggested for use as shown forcontrolling the various operating conditions desired and as signaledfrom the engine's various sensors.

[0300] Referring now to FIG. 29, there is shown a third efficient systemof scavenging the engine of FIG. 25;

Scavenging System C (FIG. 29)

[0301] This scavenging system would be that shut off valves 49′ would beclosed, (or valves 25 and 49 could be eliminated), with bottom portsopened to the atmosphere by valve 53, one inlet valve 16 leading frommanifolds 13 and 14 to cylinder 7 could be opened for a very shortperiod of time by a cam, perhaps by a small lobe on a cam that has alarge lobe to open the same valve (as 21-C in FIG. 11) at a differentcrank angle, at the same time ports 52 were uncovered by piston 22 andexhaust valves 17 were opened. The high pressure air would quickly sweepcombusted gases through ports 52 and exhaust valves 17, through theirrespective exhaust pipes 17 and 17′ to the atmosphere. The intake valve16 would close quickly, no later than the time exhaust ports 52 closed.The exhaust valve would remain open for further scavenging and for thereduction of the compression ratio of the engine. Alternatively bottomexhaust valves 53 would be closed and as bottom ports 52 were uncoveredby piston 22, exhaust valves 17 would also open earlier for blowdown,air from the airbox 51 supplied by conduit 32 would blow into ports 52and scavenge the cylinder 7 through exhaust valves 17.

[0302] During this scavenging-charging stroke the exhaust valve 17 isclosed at a point after the first 20 percent or so of piston 22 travel.At any point after exhaust valve 17 has closed, the cylinder 7 being nowfilled with fresh air, and the compression ratio having beenestablished, and before piston 22 has reached top dead center,additional (secondary) air charge, with temperature density and pressureadjusted is introduced when needed by opening a second intake valve 16and, or by another lobe 21-C on the same cam (see 21-C. FIG. 11) openingthe same intake valve again. All of the operating parameters suggestedwould depend on the duty cycle of the engines, e.g., power requirements,efficiency and emissions considerations and the fuel used. The later inthe exhaust-charging stroke the exhaust valve 17 is closed, the lower isthe compression ratio of the engine established. If closed early enoughthe effective compression ratio can be as much as 13:1 or 22:1, ifclosed later the effective compression ratio can be as low as 2:1.

[0303] An engine control module could control all of the conditionsrequired of the engine.

[0304] Referring now to FIG. 30, there is shown a fourth system ofefficient scavenging the engine of FIG. 25.

Scavenging System D (FIG. 30)

[0305] In this system exhaust blowdown occurs through the top exhaustvalves 17 and through part of the bottom scavenging ports 52′ which openjust before bottom dead center, perhaps 40°, and simultaneously with orjust after the top exhaust valves open. At the time bottom ports 52′ areopened, or shortly after, exhaust valves 17 are also opened, or, valve53 leading to bottom exhaust line 18 is already open, and exhaustblowdown occurs over the next, 40° or so after bottom dead center, withscavenging air being injected through at least one of the bottom ports52″ which has been constructed to receive pressurized air from air box55 supplied by conduit 32′ or 50 at such a time the ports 52′ are openedby piston 22 and the pressure in cylinder 7 has dropped below thepressure in air-box 55. After ports 52′ are closed, exhaust valvesremain open through a significant part of the second or exhaust-chargestroke of piston 22 for additional scavenging by positive displacementand in order to establish a low compression ratio.

[0306] During this scavenging-charging stroke the cylinder 7 being nowfilled with fresh air, exhaust valve 17 may be closed at any point afterthe first 20 percent or so of piston 22 travel. Now at any point exhaustvalve 17 can close to establish the compression ratio and inlet valve 16can open to admit a secondary pressurized air charge which has itstemperature and pressure adjusted to what is deemed proper. The later inthe exhaust-charging stroke the exhaust valve 17 is closed, the lower isthe compression ratio of the engine established. If closed early enoughthe effective compression ratio can be as much as 13:1 or 22:1, ifclosed later the effective compression ratio can be as low as 2:1. Allof the operating parameters suggested would depend on the duty cycle ofthe engines, e.g., power requirements, efficiency and emissionsconsiderations and the type of fuel used, and can be controlled by anengine control module which receives signals relating conditions incertain engine areas and which are relayed to the ECM 27.

[0307] Referring to FIG. 31, there is shown a schematic drawingdepicting an alternate arrangement in which an electric motor 34preferably drives the air compressors of an engine similar to that ofFIG. 25.

[0308] Referring now to FIG. 32, there is shown a schematic drawingshowing the 2-stroke engine of FIG. 25 and FIG. 26 and having only onecompressor 1 for supplying both scavenging and charge-air. Also shownare a shutter valve 3 and an air bypass valve 4, valves 16 and 17controlling charge and scavenging air and valves 53 and 53′ forreleasing exhaust blowdown out of the cylinder bottom ports 52 throughexhaust conduit 18 to the atmosphere. Thus the engine of FIG. 32 canperform all of the feats described for the engine of FIG. 25 anddescribed for the engine of FIG. 25, FIG. 26, FIG. 27, FIG. 28, FIG. 29,FIG. 30 and FIG. 32. Also shown is an engine control module (ECM) 27,and connections to various valves in order to manage the charge andscavenging air temperature, density, weight and pressure, and thepressure and path of the scavenging air to achieve the desired resultsfrom the engine. Arrows show the paths possible for the heated (hollowarrows) air and the cooled (solid arrows), air, and for the charge-airto pass through the air bypass valve 4, all in order to adjust airpressure, density, weight and temperature for optimum engineperformance.

The Engine 100 ³³ System of FIG. 33

[0309] Referring now to FIG. 33, there is illustrated a six cylinderinternal combustion engine in which part of the cylinders 62 through 65are used for producing power and two of the cylinders, cylinders 66 and67, are used for compressing the air necessary to operate the engine. Asupercharger 57, in this case preferably a Lysholm type, is used toboost the atmospheric pressure air received through air intake 8′,before the air enters compressor cylinders 66 and 67. A shutter valve 3′and air bypass valve 4′ re-circulate the charge-air back throughcompressor 57 when both are open, to lessen compressor work and reducecharge densities for light-load operation. When air bypass valve 4′ isclosed shutter valve 3′ can open or close to send the air charge to thecylinders cooled or uncooled, respectively, in order to managecombustion temperatures and temperatures for optimum performance.

[0310] The second stage of compression is transferred from compressioncylinders 66 and 67 through conduits 201, 202 to shutter valve 4″ which,when closed, sends the compressed charge through conduit 204 andintercooler 11 and conduit 205 to the engine manifold 58′ in a cooledcondition. If opened, shutter valve 4″ directs the charge away fromcooler 11 through conduit 203 and 205 to the power cylinders withoutcooling.

[0311] By having its camshaft arranged to rotate at one-half crankshaftspeed, the engine 100 ³³ operates in a 4-stroke cycle, with a lowcompression ratio, an extended expansion ratio and high mean effectivecylinder pressure when operated in a manner just as described herein forthe engine of FIG. 3.

[0312] Alternatively, the engine of FIG. 33, with one or more of itscylinders acting as compressor cylinders and having its camshaftarranged to rotate at crankshaft speed, operates in a 2-stroke cyclewith the low compression ratio, high mean effective cylinder pressureand an extended expansion ratio when operated in the manner describedherein for the engines of FIG. 8, FIG. 9 and FIG. 11.

[0313] Still referring to FIG. 33 of the drawings, additional fuelsavings can be achieved in any of the engines of the present inventiondescribed hereinbefore by use of an economizer constructed as an aircompressor retarder brake. For discussion of the disclosed retarderbrake, this six-cylinder engine 100 ³³ represents any of the engines ofthis invention which use externally compressed air (FIG. 1 through FIG.33) to either fully supply charge-air or which use it to enhance engineperformance. The air retarder brake illustrated has a compressor 57Aoperatively connected to the drive shaft of the vehicle (not shown) orgeared to the engines crankshaft 20 and stores energy produced duringbraking or downhill travel which is utilized to supply compressed air tothe engine power cylinders via the transfer manifold 58. Such aneconomizer is coupled with an air reservoir 59 and during the time inwhich the economizer reservoir air pressure was sufficiently high foruse in the power cylinders of the engine, the engine compressor can beclutchably disengaged or air pumped by the compressor(s) can be bypassedback to the inlet of the compressor(s) so that no compression work wouldbe required of the compressor. A relief valve 60 prevents excess buildup of pressure in the air reservoir. A valve 61 (being in thisarrangement, a reversible one-way valve) allows air from the reservoirto be transferred to the manifold when the pressure in the reservoir 59is higher than in the transfer manifold 58, if the air is needed. In thecase of engine constructions having compression cylinders, eachcompression cylinder of the engine can also be deactivated during thisreserve air operation time by shutting off the admission valve so thatno net Work would be done by the compressor(s) until themanifold-reservoir pressure dropped below operating levels. Severalsystems of deactivating cylinder valves are described in the art and/orhave been mentioned previously.

[0314] In an alternate arrangement, the compressor 57A is eliminated andthe air storage tank 59 is used to store excess air compressed by thecompressor cylinders of the engine during braking and downhill travel.In this case, the valve 61 is a two-way valve and a blocking valve 70 isplaced in the manifold 58 between the compressor cylinder(s) 66, 67 andthe working cylinders 62-65. During downhill travel or during braking,the blocking valve 70 between compressor and working cylinders is,preferably, closed, power cylinders 62-65 are deactivated, and thetwo-way valve at 61 is utilized in order to divert the air compressed bythe compressor cylinder(s) into storage tank 59.

[0315] When it is desired to operate the engine normally, the blockingvalve 70 between the compressor and the expander cylinders is opened andthe two-way valve 61 is closed. During reserve air operation, both theblocking valve 70 and the two-way valve 61 are opened. If desired, thecompressor cylinder(s) 66, 67 are deactivated while in the reserve airoperation mode, as described earlier. Also, a Jacob brake (a prior artretarder brake) could supply compressed air to the air reservoir tank.

[0316] Operating the engine on reserve air supply would improve the meaneffective pressure (mep) of the engine for 20 percent improvement inpower and efficiency, while reducing polluting emissions, during thetime the engine was operating on the reserve air.

[0317] This feature would produce additional savings in energyespecially in heavy traffic or in hilly country. For example, an engineproducing 100 horsepower uses 12.7 pounds of air per minute. Therefore,if energy of braking were stored in the compressed air in the economizerreservoir 59, a ten or fifteen minute supply of compressed air can beaccumulated and stored during stops and down hill travel. When thereservoir pressure drops below the desired level for efficientoperation, a solenoid (not shown) is used to reactivate the compressioncylinder valves and they (with the supercharger, when needed) will beginto compress the air charge needed by the engine.

[0318] Using the air reservoir 59, the engine needs no compressionbuild-up for starting and as soon as the shaft was rotated far enough toopen the intake valve, the compressed air and fuel would enter and beignited for “instant” starting. Furthermore, the compressed air could beused to rotate the engine for this means of starting by opening intakevalves earlier than usual to the expander cylinders to begin rotationand firing as is common in large diesel engines, thus eliminating theneed for a starter motor. Alternatively, the compressed air could beused to charge a “hydrostarter” to crank the engine as is common on someheavy-duty diesel engines.

[0319] In an alternate, and still preferred embodiment, the reserve airin reservoir 59 is additionally used to “motor” the engine to allow avehicle such as a bus to pull away from a stop and operate fuelless for30-60 seconds or more, which is the time that greatest pollution occursin bus or stop-and-go delivery vehicle operation.

REMOTELY COMPRESSED AIR EMBODIMENTS

[0320] Referring now to FIG. 34, there is seen a schematicrepresentation of an engine 100 in accordance with an alternateembodiment of the present invention for externally providing charge-airfor marine, locomotive, stationary, or electric power generatingengines, or any engine applications of this invention, constant orvariable load and speed, which have adequate electric power or waste or“bleed” air available. In FIG. 34. a remote electric air compressor 35preferably With one or more intercooled compression stages, preferablysupplies temperature conditioned charge-air (both high and low pressure,if needed) for one or more engines of this invention. The charge-air,conditioned in temperature and pressure, is supplied directly tomanifolds 13 and 14 by conduit 15AE from compressor 35. The engineintake conduit 9 of, for example, FIG. 4, or low-pressure conduits 32 ofother engines of this invention receive air from the atmosphere oralternatively receives low pressure air from a low pressure conduit 15BEfrom compressor 35.

[0321] An alternate arrangement, also depicted in FIG. 34, for providingcombustion charge-air for any of the engines 100 of the presentinvention is to provide charge-air from conduit 1 5AR which supplieswaste or “bleed” air produced in industrial processes. The air issupplied either at 1 or 2 pressure levels. The lower pressure, ifneeded, preferably is supplied by dropping the pressure from the mainincoming waste air conduit 15AR with a pressure regulator valve (25 aleading to low-pressure conduit 15BR). The arrangement is similar to thearrangement of conduits 15-A, 15-B and valve 25 in, for example, FIG. 5,with conduit 15-A representing the supply conduit 15AR from the wasteair supply, and with conduit 15-B representing conduit 15BR in FIG. 34.

[0322] The use of remotely compressed air, either waste air or fromcompressor 35, eliminates the engines compressors 1, 2 intercoolers 10,11, 12, certain conduits and valves 3, 4, 5, 6 of the charge-air supplyequipment, providing the 10 air has been conditioned during or after thecompression process (and prior to introduction to the manifolds 13, 14).Thus, the equipment of the engine 100 of the various embodiments shownthroughout the various drawing figures of the engine 100 embodiments ofthis invention, is preferably eliminated up to those points designatedby dashed lines A. B and C throughout the various drawings. Thecharge-air from either of the aforementioned remote sources ispreferably introduced into the engines near the manifolds 13 and 14 and,in the appropriate embodiments, the low air pressure from the remotesources is introduced at conduit 32, as shown in FIG. 34.

[0323] In the remotely charged engines, the fuel can be carbureted priorto compression, can be throttle-body injected, port-injected, ordirectly cylinder injected.

Regarding Pollution Control

[0324] Referring now to FIG. 2 and FIG. 4-C there is shown a method offurther reducing polluting emissions in any of the engine embodiments ofthis invention which includes re-burning a portion of the exhaustedgases when and if required. In the 4-stroke engines of FIG. 1-FIG. 3 andin the 2-stroke engines herein depicted having a single air intake, theexhaust outlet conduit(s) 18 have a shunt conduit 202 (refer to FIG. 2)leading from a port 206 in the side of exhaust conduit 18 to a port 204in the side of intake-conduit 8. A proportioning valve 201 is situatedat the intake port 204 and is arranged to selectively restrict the flowof fresh air into conduit 8, while at the same time opening the port 204to the exhaust conduit to selectively allow entry of exhaust gases tothe intake conduit 8. This valve is variable and mechanically,electrically or vacuum solenoid operated and preferably controlled by anengine control module (ECM) or control 144 in FIG. 35 and FIG. 36. Thisallows the re-burning of a portion of the exhausted gases, the amount ofpercentages thereof being adjusted by the engine control module inresponse to various sensors, such as an oxygen sensor, placed instrategic positions in the engine. Exhausted gases passing throughconduit 202 can be cooled by either optional cooling fins 202 a or bypassing through an optional intercooler (not shown) before reaching theair intake conduit 8.

[0325] With reference to FIG. 4C. in engines having only one atmosphericintake conduit but having different air paths and conduits, such asconduits 15-A and 15-C of FIG. 4B, a shunt conduit 202′ leading from theexhaust conduit 18 is divided into two shunt conduit portions 203 a, 203b, each with a proportioning valve 209 a, 209 b operating so as toselectively admit exhausted gases to either or both of intake valve 16-B(through conduit 9 and eventually conduit 15-C) or to intake valve 16-A(by way of conduit 8 and conduit 15-A). Each proportioning valve 209a.209b would allow either a portion or none of the exhausted gases toenter its respective port, meanwhile restricting entrance of fresh airif necessary. The exhausted gases can be cooled by optionally arrangingfins 202 a on conduit 202′ and/or 203 a, 203 b and 203 c or by passingthe exhaust through an optional intercooler (not shown) before the gasesare introduced into the air intake(s) of the engine.

[0326] Alternatively, as shown in phantom on FIG. 4C, one shunt portion203 a is diverted (shown as 203 c) directly to conduit 15-C and providedthere with a proportioning valve 209 c.

[0327] In the engines of FIG. 4 and FIG. 7 having dual atmospheric airintakes 8, 9, an arrangement similar to that shown in FIG. 4C isutilized, it being understood, however, that conduit 8 is open to theatmosphere.

[0328] In any engines having dual air intake conduits or dual air pathsa portion of exhausted gases can be introduced in any amount necessary,in from one to three points and controlled preferably by an enginecontrol module (ECM) for better management of combustion and emissionscharacteristics.

[0329] This re-burn feature is of particular importance with diesel fueloperation.

Constant Load and Speed Engines

[0330] Whereas the preponderance of the foregoing specificationdescribes embodiments and representative engines of the presentinvention which are optimized for vehicular (marine, truck bus,automobile, tank, train and plane) duty cycles and describe systems andmethods for varying power, torque and speed, the present invention findsuseful application for obtaining high power and torque while maintainingoptimum fuel economy and low polluting emissions in less complexengines, such as, for example, constant load and speed engines. FIG. 35and FIG. 36 depict alternate embodiments of the present invention whichembodiments are representative of constant load and speed engines (e.g.,for electric power generation and in other stationary or industrialengine applications, e.g., for pumps and compressors) outfitted inaccordance with the principles of the present invention.

The Engine of 100 System of FIG. 35

[0331] Referring now to FIG. 35 there is shown is a schematicpresentation of an engine which represents any of the 4-stroke or2-stroke engines of the present invention outfitted for constant loadand speed operation. The basic components of the engine 100, such ascompressors 1, 2 and optional intercoolers 10, 11, 12 (shown in phantom)and their necessary associated conduits are, preferably, designed foroptimum operating parameters having only the basic components. Thevarious controls, shutter valves, air bypass valves and their associatedbypass conduits such as those in previously described embodiments, arepreferably eliminated in order to reduce weight, cost and complexity ofoperation. In FIG. 35, the engine 100 is shown as outfitted with a firstancillary compressor 1 and a second ancillary compressor 2, optionalintercoolers 10, 11, 12 (shown in phantom) and interconnecting conduits,all operating as would be understood with reference to the previousdetailed descriptions and operating with two stages of pre-compressionof the charge-air, intercooled or adiabatically compressed.

[0332]FIG. 35 shows a preferred setup for power generation with any ofthe engines of this invention. The power output shaft 20 of the engine100 is coupled schematically by line 140 to power input shaft 20″ ofgenerator 141 which has electric power output lines 142. As the shaft 20of the engine 100 rotates the shaft 20″ of generator 141, the amount ofelectric power produced by generator 141 is detected by sensor 143 andrelayed to control unit and governor 144 which contains various relaysand integrated circuits to quantify the power output and to sendmessages by line 145 to fuel/air control (not shown) on fuel line 148and throttle 56, and/or by line 149 to spark control to advance orretard the spark in spark-ignited engines and/or to send messagesthrough lines 146 and 146b for engines having fuel injection systems,e.g. for natural gas, gasoline or diesel fuel, or to fuel/air controls,all in order to control the fuel input, speed and output of engine 100and hence the output of generator 141. Control unit 144 also sendssignals to control the proportioning valve 201, shown in FIG. 4 and toproportioning valves 209 a, 209 b, 209 c shown in FIG. 2 to control theamount, if any, of exhaust recirculated by these valves for re-burn inany engine of this invention utilizing this feature. Further explanationof the components and operation with the engine 100 of the presentinvention is deemed unnecessary as it would be understood by thoseskilled in the art having reference to the present disclosure.

[0333] The optional intercoolers 10, 11, 12 (shown in phantom) arepreferably used for gaseous or gasoline fueled engines and arepreferably eliminated or reduced in number or cooling capacity in thecompression-ignited engine, this being made possible by low peakpressures and temperatures in the engines of this invention.

[0334] Referring now to FIG. 36 there is shown an engine illustrated asa 2-stroke engine but representing any of the engines of the presentinvention, 2-stroke or 4-stroke, which is coupled schematically by line140 with an electric generator 141. The engine and arrangements aresimilar in structure and operation as that shown and described for theengine of FIG. 35 with the exception that engine of FIG. 36, operatingas either 2-stroke or 4-stroke cycle engine 100, has only a single stageof pre-compression, optionally intercooled by intercoolers 11, 12 (shownin phantom), of the charge air. As with the engine of FIG. 35,intercoolers 11, 12 are preferably eliminated or reduced in coolingcapacity in compression-ignited versions of the engine 100 of thisinvention. Also, as with the engine 100 of FIG. 35, the governor, andother controls and the operation of the engine and generator would beunderstood by those skilled in the art having reference to the presentdisclosure.

[0335] It will be seen by the foregoing description of a plurality ofembodiments of the present invention, that the advantages sought fromthe present invention are common to all embodiments.

[0336] While there have been herein described approved embodiments ofthis invention, it will be understood that many and various changes andmodifications in form, arrangement of parts and details of constructionthereof may be made without departing from the spirit of the inventionand that all such changes and modifications as fall within the scope ofthe appended claims are contemplated as a part of this invention.

[0337] While the embodiments of the present invention which have beendisclosed herein are the preferred forms, other embodiments of thepresent invention will suggest themselves to persons skilled in the artin view of this disclosure. Therefore, it will be understood thatvariations and modifications can be effected within the spirit and scopeof the invention and that the scope of the present invention should onlybe limited by the claims below. Furthermore, the equivalents of allmeans-or-step-plus-function elements in the claims below are intended toinclude any structure, material, or acts for performing the function asspecifically claimed and as would be understood by persons skilled inthe art of this disclosure, without suggesting that any of thestructure, material, or acts are more obvious by virtue of theirassociation with other elements

What I claim is:
 1. An internal combustion engine, comprising: an engineblock defining at least one cylinder therein, an inlet portcommunicating between said cylinder and a source of air, and an exhaustport through which air is exhausted from said cylinder; a piston movablymounted within said cylinder; an intake valve selectively occluding saidintake port; an exhaust valve selectively occluding said exhaust port; acompressor in fluid communication between said source of air and saidinlet port, whereby at least part of the intake air is selectivelycompressed by the compressor prior to entering the cylinder.
 2. Theengine of claim 1, further comprising at least one air coolerinterconnected between said compressor and said inlet port.
 3. Theengine of claim 2, further comprising an air delivery network including:conduit interconnecting said source of air, said compressor, said aircooler, and said inlet port; and means for selectively controllingoperation of said compressor to operate in either a compress modegenerating a compressed air charge or a pass mode passing airtherethrough without compressing.
 4. The engine of claim 3, wherein saidair delivery network further includes means cooperating with said meansfor selectively controlling operation for selectively controlling theair charge characteristics selected from one or more of density,pressure, temperature, and the mean and peak pressure within saidcylinder.
 5. The engine of claim 4, wherein both of said means forselectively controlling comprise a common plurality of valvesstrategically placed along said conduit and a common engine controlmechanism controlling the operation of said valves.
 6. The engine ofclaim 5, further comprising: a second compressor in fluid communicationbetween said compressor and said inlet port, whereby at least part ofthe intake air is selectively compressed a second time prior to enteringthe cylinder; and wherein said delivery network includes means forcontrolling the operation of said second compressor: and wherein saidmeans for selectively controlling the air charge characteristicscooperates with said means for controlling the operation of saidcompressor and with said means for controlling the operation of saidsecond compressor for selectively controlling the air chargecharacteristics selected from one or more of density, pressuretemperature, and the mean and peak pressure within said cylinder.
 7. Theengine of claim 1, wherein said compressor is a reciprocatingcompressor.
 8. The engine of claim 7, wherein said reciprocatingcompressor includes a piston connected to the engine crankshaft.
 9. Theengine of claim 1, wherein said compressor is a rotary compressor. 10.The engine of claim 1, further comprising: a second compressor in fluidcommunication between said compressor and said inlet port, whereby atleast part of the intake air is selectively compressed a second timeprior to entering the cylinder.
 11. The engine of claim 10, wherein saidengine block defines a second inlet port opening to said cylinder, andwherein said engine further comprises: at least one an air cooler; anair delivery network including: conduit interconnecting said source ofair, said compressor, said second compressor, said air cooler, saidinlet port and said second inlet port; and means for selectivelycontrolling operation of said compressor to operate in either a compressmode generating a compressed air charge or a pass mode passing airtherethrough without compressing. means for selectively controllingoperation of said second compressor to operate in either a compress modegenerating a compressed air charge or a pass mode passing airtherethrough without compressing. means for selectively directing acompressed air to said first inlet port and uncharged air to said secondinlet port.
 12. In an internal combustion engine having a crankshaftdriven by at least one piston moving through at least a compressionstroke and an expansion stroke aided by combustion taking place within acylinder, wherein the compression stroke results in the compressing ofair and gaseous fuel within the cylinder, the improvement theretocomprising: an external compression stage in which an air charge iscompressed outside the cylinder; and delivery conduit linking saidcompression stage to the cylinder.
 13. The improvement of claim 12,further comprising an intercooler through which said air charge isselectively directed from said external compression stage.
 14. Theimprovement of claim 12, further comprising a second externalcompression stage in which said air charge is compressed a second timeoutside the cylinder.
 15. A method of operating an internal combustionengine having a crankshaft driven by at least one piston moving throughat least a compression stroke and an expansion stroke aided bycombustion taking place within a cylinder, wherein the compressionstroke results in the compressing of air and gaseous fuel within thecylinder, said method comprising the step of managing air chargedensities, temperatures, pressures, and turbulence.
 16. The method ofclaim 15, wherein the managing step includes at least the steps ofcompressing an air charge prior to the compressing within the cylinder,thus generating a pre-compressed air charge.
 17. The method of claim 16,wherein the managing step further includes at least the step ofselectively channeling the pre-compressed air charge through a coolingdevice prior to delivery to the cylinder.
 18. The method of claim 17,further comprising the step of providing a compression ratio lower thanthe expansion ratio of the engine.
 19. A method of operating an internalcombustion engine, said method comprising the steps of: (i) producing anair charge; (ii) controlling the temperature, density and pressure ofthe air charge; (iii) transferring the air charge to a power cylinder ofthe engine such that an air charge having a weight and density in arange ranging from below atmospheric weight and density to aheavier-than-atmospheric weight and density is introduced into the powercylinder; (iv) then compressing the air charge at a lower-than-normalcompression ratio; (v) causing a pre-determined quantity of charge-airand fuel to produce a combustible mixture; (vi) causing the mixture tobe ignited within the power cylinder; and (vii) allowing the combustiongas to expand against a piston operable in the power cylinder with theexpansion ratio of the power cylinders being substantially greater thanthe compression ratio of the power cylinders of the engine.
 20. Themethod of claim 19, further comprising the steps of: repeating steps (i)through (vii); and periodically selectively varying the weight anddensity of the air charge from one transferring step to anothertransferring step.
 21. The method of claim 19, further comprising thesteps of: repeating steps (i) through (vii); and maintaining the weightand density of the air charge at substantially the same pre-selectedweight and density during each of the repeated transferring steps. 22.An internal combustion engine, comprising: at least one ancillarycompressor for compressing an air charge; an intercooler through whichthe compressed air is selectively directed for cooling; a plurality ofpower cylinders in which the combustion gas is ignited and expanded; apiston operable in each power cylinder and connected to a crankshaft bya connecting link for rotating the crankshaft in response toreciprocation of each piston; a transfer conduit communicating thecompressor outlet to a control valve and to said intercooler; a transfermanifold communicating the intercooler with the power cylinders throughwhich manifold the compressed charge is transferred to enter the powercylinders; an intake valve controlling admission of the compressedcharge from the transfer manifold to said power cylinders; and anexhaust valve controlling discharge of the exhaust gases from said powercylinders.
 23. A method of operating an internal combustion engine, saidmethod comprising the steps of repeatedly compressing air charges withina cylinder of the engine and producing mean effective cylinder pressurewithin the cylinder which mean effective cylinder pressures range overtime from lower-than-normal to higher-than-normal.
 24. The method ofclaim 23, wherein the maximum cylinder pressure remains below normal.